Harrington threw three touchdown passes to help the Miami Dolphins erase a 10-point deficit and roll to a 27-10 victory against Detroit.
"It's nice to have that feeling in this building," he said. "As much as I tried to downplay it and needed to downplay it for the sake of this team, there was still a lot of emotion coming here."
The quarterback was drafted third overall in 2002 by the Lions, who traded him in May for a conditional draft pick that could be a fifth-rounder.
Harrington entered the game 1-3 on Thanksgiving with no TDs, five interceptions and an average of 153 yards passing. In the first half alone against his former team, he threw for two scores, an interception and 154 yards. Harrington finished 19 of 29 for a Thanksgiving-high 213 yards, three TDs and an interception.
Miami (5-6) has won four straight -- doubling Harrington's longest winning streak in any of his four seasons in Detroit. The Lions (2-9) dropped their third straight in a game that ended much differently from the way it began.
Detroit went ahead 10-0 on its first two drives and held Miami to 6 yards on its first possession.
Harrington's second TD pass put Miami ahead with 1:55 left in the first half and his third made it 24-10 late in the third.
Detroit's Roy Williams had five catches -- all for first downs -- for 110 yards in the first quarter, then didn't have another reception until early in the fourth. He finished with 126 yards receiving.
Kitna has had a lackluster season and his shaky offensive line, which couldn't even slow Miami's three-man rushes, prevented that from changing against the Dolphins. He was 22-for-40 for 252 yards with a TD, an interception and a fumble.
Harrington directed a balanced attack, led by Marty Booker's seven receptions for 115 yards and two TDs. Ronnie Brown ran for 68 yards before leaving with a hand injury early in the third quarter, and Sammy Morris filled in well with 91 yards rushing -- including a 55-yard run.
The fans at Ford Field, where Harrington was booed last year at a practice, jeered him when he was introduced before the game and shown on the video boards while Billy Joel's Piano Man played -- a jab at the quarterback's piano playing.
They booed Harrington when he ran on the field for his first drive and every time he was shown early in the game on the video boards, which displayed numerous close-up shots of his face.
"It's a shame people can't appreciate what he tried to do for this organization," Miami coach Nick Saban said. "To be honest for you, I don't have a lot of respect for what they did."
By the third quarter, the fans stopped booing Harrington and directed their frustration at team president Matt Millen with the loudest "Fire Mil-len!" chants of the season.
Detroit is an NFL-worst 23-68 since Millen took control of the franchise in 2001.
"Matt's not down here playing football, we are," Lions linebacker Boss Bailey said. "If they want to chant 'Fire Millen,' they should be chanting to fire the whole damn team. All Matt does is bring in players, and every year we talk about how much talent we have. So it should be on us. This isn't about Matt."