On June 12, 2008, Allen would play all 48 minutes and contribute greatly with 19 points and 9 rebounds in what would become the largest comeback in NBA Finals history, with the Celtics coming back from a 24-point deficit at one point in the second quarter and a deficit as large as 20 in the third. In that game, Allen would make the game clinching layup with 16.4 seconds remaining to give the Celtics a 5-point lead and put the game away.