Damon was once the head chemist of Satine Cosmetic's R&D department with fellow-chemist and love interest Vanessa Lerner. His eccentric methods and lack of interest in business politics led him to resign to pursue a life of peace and solitude, living on a ranch in Georgia raising thoroughbred horses. In 2003, Damon Porter arrived in Genoa City intrigued by a phone call from Drucilla Winters to discuss a potential business position with Jabot. Although Neil initially contacted Damon to return to Satine, Drucilla found Damon's business card and snatched it. Dru went way above her authority but wooed Damon to work on developing a competing product while Ashley took maternity leave. When Jack found out, he reprimanded her, but was pleased that they had won Damon Porter over Newman. Ashley was not pleased, but after meeting Damon she welcomed him to Jabot.
Into meditation and incense, and turned off by office politics, the laid-back, tall and handsome Damon Porter was quite a unique quantity in Genoa City, so women were quite attracted to him. Phyllis Abbott accidentally ran into Damon at Jabot. She failed to mention she was married to Jack, and causally flirted with Damon. After Brad discovered Victor hired Michael Baldwin, he filled Damon in on Phyllis and suggested that Damon pursue her to find out Victor's plans. Damon refused to get involved in the Cosmetic Wars and went to Yves Restaurant. Seeing Phyllis there alone after her latest fight with Jack, he invited her for dinner. At first Phyllis said no, but Damon put on the charm, and she consented. During dinner, Jack and Diane walked in together. A slightly inebriated Phyllis tried to make a scene, but Damon got her out of there to cool off at his apartment where she confided in him. Later they shared a lusty and passionate kiss, but Phyllis quickly left before it got out of hand.
Many a business consultation or Tuvia product demonstration in the lab between Dru and Damon has turned into a very sexy encounter between her flirting and his charm. The ever-nosy Dru also showed up at his apartment several times to grill him about her suspicions of Phyllis, once even getting the doorman to let her in, and listening to his answering machine messages.
Damon first met Victoria Newman one night at Yves. Not realizing he was Jabot's head chemist, she poured out her feelings to him. Later, when she found out he was Damon Porter, she was outraged, and told him off. But Victoria was only further intrigued by the cool and collected Mr. Porter and they realized they really had a lot of things in common. They both loved riding horses, so Victoria invited him for a ride at the ranch. Once her mother Nikki realized Victoria and Damon were getting close, she warned Damon to stay away from Vickie. Victor also asked Michael to keep them apart, and he found himself falling for Victoria too. One day Vikki came over to Damon's apartment, and as he spoke to her about his interests and dislike for the two companies being at war, she told him to kiss her, and the two shared a long, passionate kiss.
Damon finished creating the Tuvia products in time for the rollout. Jabot was hurting financially, but saw Tuvia as their savior, depending on their reputation and fine product to put them back in the black. But Victor could not let Jabot win the war, so blackmailed Michael Baldwin into paying off large retailers to give them the prime shelf space normally held by Jabot. Tuvia still outsold Safra, but only by a slight margin. Even after Diane invested heavily and bailed them out, Jabot really needed a miracle now. Enter Damon's old flame and co-worker, Vanessa, who came looking for him with a discovery of a rare orchid whose extract could straighten hair. If an orchid could be found and they could find a way to synthesize it, Jabot would have their miracle. Damon decided to go to Ryukyu Islands, Japan, to secretly hunt for the orchid. But nosey Dru found out and relocated her wedding to Japan. Damon and Vanessa found themselves in the midst of the enemy as they joined Dru and Neil on the Newman jet for Japan when Neil brought along his close friend Phyllis, then Jack insisted on going too. While the others prepared for the wedding Damon and Vanessa went orchid hunting to no avail. But when they attended the lavish wedding, they discovered one - in Drucilla's wedding bouquet! Unable to get it away from Phyllis who caught the bouquet, they interrogated Dru's daughter Lily as to where she had found it, and managed to find another. In an effort to make up with Jack, Phyllis gave Jack her orchid. When Phyllis found out that Jack already had one, yet accepted hers, she stole them both from the Jabot lab, quit her job at Newman and left town.
Phyllis later returned intending to give the orchids to Newman, but Diane stole one orchid for herself, and made a deal with Phyllis that she could have the other only if she gave it back to Jack, which Phyllis did. Ashley has since stopped work on the project, but Jack insists it is on. Phyllis dealt the final blow to their marriage by testifying on Victor's behalf at his commercial bribery trial. Jack filed for divorce several arguments later. Damon and Phyllis became lovers, infuriating Vanessa, who retaliated by offering her project to Newman. When Jack discovered Damon and Phyllis were together, he fired Damon, but Ashley has since hired him back. Phyllis moved in with Damon, and he was helping her deal with her demons through meditation and talking things out. But when Phyllis's teenage son Daniel returned, whom she had not seen since he was a toddler, he wanted her to move in together so they could bond. Unable to find a suitable apartment, Phyllis and Daniel accepted Victor's offer to live in Victoria Newman's house on the Newman Ranch. Damon and Daniel did not get along, Damon called him Slick, and Daniel resented him. Daniel has met Jack, and they hit if off right away, and Daniel could tell that his mother and Jack still love each other.
Finally, Damon confided in Phyllis his dark secret which has kept him so aloof from her and everyone for 8 years. He had a son who died, who would have been the same age as Daniel, which is why he reacts to him so. They lived in Atlanta, Georgia, and Elias loved horses, wanted to be an Olympic champion. Damon and Elias had been riding horses, stopped at a fast food joint, and were eating their burgers, when they were harassed by some street kids. Damon put them straight. As he was using the encounter as a lesson to Elias on the way home in the car, a car drove up, and the punk Dominic Hughes fired a shot. The shot meant for Damon hit Elias, and the boy died in his father's arms. Damon changed, he bought a gun, was consumed with revenge hunting down his killer. Hughes was finally captured, tried, and convicted to prison, but the rage was still there. He wasn't there for his grieving wife Adrianne, and she couldn't bear to be around him, so they were divorced. Years later, reality finally set in that mourning wouldn't bring Elias back. Damon learned to build a facade of control through meditation to cover the rage that was always still there. Daniel learned to respect Damon when a kid named Alex came after him and his friend Kevin to even the score for a favor unpaid. Phyllis tried to get between them, but Damon arrived and saved them both, scaring the kid off.
Damon got word that Hughes was up for parole and began spending his time contemplating his Samurai sword , so Phyllis visited Hughes in prison to warn him to stay away, because Damon still wanted to kill him. Dominic told her he already knew that Damon lived in Genoa City, and he fully intended to head there upon his release. He claimed he was born again and had to see Damon to plead for his forgiveness. Phyllis left, and Dominic sneered behind her back. He did get paroled, and showed up in Genoa City immediately. Phyllis met him and brought him to Damon, hoping to help Damon keep his cool. Damon didn't believe a word until Dominic showed him the tattoo on his inner arm in memory of Elias. Later Damon felt sorry for the guy, spending his parole money on a trip to see him, so sent Phyllis to deliver some cash to Dominic. As Phyllis approached his motel room door, another thug leaving and discussing a heist they were going to pull, and how they suckered Damon. Phyllis made a call on her cell phone, then daringly burst into Dominic's room. Dominic pulled a gun, threw her on the bed intending to rape her, as Damon broke down the door wielding his Samurai sword. Hughes was knocked down and his gun flew across the floor. Phyllis convinced Damon not to kill him, but when she stepped between them, Hughes went for the gun. Damon jumped between them as Hughes fired and Damon took the bullet. With a last surge of rage, Damon ran Dominic through with the sword. Both were rushed to the hospital, where Phyllis hissed, "I hope you die!" to Dominic's as his gurney passed.
Damon was near death in the ER, and his spirit left his body and stood by Phyllis as she frantically watched them work over him. The spirit of Elias appeared and told Damon it wasn't his time, to return to Phyllis who needed him. Elias forgave Damon for not protecting him, and that he would always be in Damon's heart. Damon lived. While still in the hospital recovering, Damon and Phyllis were questioned for suspicion of conspiracy to murder Dominic, thanks to the lies Hughes told the police. Phyllis had to grovel to Christine to represent her, and although Christine said no, Daniel talked her into taking the case. Phyllis decided it was time for drastic measures, dressed up as a man, got thrown in jail for drunk driving, and attempted to get Dominic to confess. But Dominic recognized her, Phyllis was arrested, then later Damon, so Phyllis hired Michael Baldwin to be her lawyer instead. Things were looking bleak, so Phyllis pulled another disguise as Atlanta reporter Sandra King. Her interview questions of DA Glenn Richards helped him doubt that the felon Dominick was telling the truth. Michael took over the case and broke Dominick's story in questioning before the DA, and charges against Damon and Phyllis were dropped.
Damon's ex-wife Adrienne arrived in Genoa City from Africa where she spent years getting over him and the tragedy of losing their son, and they reconciled and returned to his ranch in Atlanta.