Jacksonville then went on a 95-yard touchdown march to take the lead around the two-minute warning.
On the ensuing possession, Harringon again was intercepted, this time when he tried to hit Chambers down the right sideline and underthrew him.
That second pick set up another Jaguars touchdown, and the Dolphins went into the locker room trailing 17-7.
The offense did very little in the second half, while the defense held Jacksonville in check until Maurice Jones-Drew burst through a crowd near the line of scrimmage and escaped for a 32-yard touchdown.
The Dolphins marched to a field goal late in the game, then made it interesting after Chambers went up high to tip Olindo Mare's onside kick to himself and recovered it.
The Dolphins quickly drove down the field, but Derek Hagan dropped a pass near the goal line, Wes Welker dropped anotehr one near the 5-yard line and Harrington then threw incomplete on fourth down to end the Dolphins' hopes.
Despite the significant of Harrington's two picks, the loss wasn't all his fault because the Dolphins got outplayed by what looked like a better team.
The Dolphins had problems with the Jaguars' big receivers, they didn't consistently block Jacksonville's defensive line and they couldn't keep David Garrard in check.
But it was pretty obvious that everything changed after Harrington's first interception.
The Dolphins came out incredibly sharp and looking like they would extend their winning streak. But after the pick, the Dolphins looked more like the team that started the season 1-6.
Well, the Dolphins now stand are 5-7, which is exactly the record they had after 12 games last season.
But somehow this just feels more disappointing.