LSU will be the seventh seed in the SEC tournament and get a first-round bye, while the Bulldogs will get a double-bye as one of the top four seeds.
Georgia opened up a 12-point lead when Nemanja Djurisic spun out of nifty post-up move for an easy layup that made it 47-35 with about 14 minutes left. The basket capped a 9-0 run comprised of Djurisic's first three baskets of the game and Gains' 3.
LSU responded with seven straight points, highlighted by senior Shavon Coleman's 3, to trim it back to 47-42, but Georgia's Donte Williams snapped the run with a dunk in transition, and LSU never got closer than five points again.
Georgia dominated in some key statistical categories, outshooting LSU 47.9 percent (23 of 48) to 36.4 percent (20 of 55) and outrebounding the Tigers 37-29.
Neither team led by more than four points in a close first half that included 10 lead changes.
Stringer provided nearly half of LSU's offense during the opening 20 minutes, when he had 13 points, most of which came on three 3-pointers.
Georgia shot 52.4 percent (11 of 21) in the first half, with Gaines making four of his first five shots for 12 points.
But the Bulldogs hurt themselves with some early ball-handling blunders. Of their 16 turnovers in the game, they committed 13 in the first half, which lead to 11 LSU points.
That allowed LSU to get up more shots and stay close despite hitting only 10 of 28 from the field.
The Tigers led 28-24 after O'Bryant's jumper, but failed to score again during the last 2:39 of the half. Georgia, meanwhile, put together a 6-0 run, highlighted by Gaines' 3, to put the Bulldogs up 30-28 at halftime.