George, a Baylor signee, did what he could for the second-ranked Ascenders, including knocking down a pair of game-tying 3-pointers at the end of regulation and the first overtime.
Holloway finished with 20 points for the Lakers, who take on Montverde Academy on Friday at the New Jersey event.
Trailing 70-60 with 2:30 remaining, the Ascenders went on a furious fourth-quarter rally that began with a
Jarace Walker layup and a 3-pointer from Memphis pledge
Noah Batchelor to cut the deficit to five with 90 seconds left.
But La Lumiere bumped it back to nine on a mid-range floater from Notre Dame signee
J.J. Starling and two free throws from Michigan State pledge
Jeremy Fears with 45 seconds remaining.
Batchelor's contested 3-pointer from the left corner cut the Lakers lead to 74-68 with 35 seconds remaining before a turnover Walker's and-one trimmed the edge to 74-71. An exchange of La Lumiere free throws and IMG buckets set up the George's first game-tying basket.
A missed Lakers' freebie opened the door as George dribbled up the right wing and pulled up for a contested 3-pointer over Starling, hitting nothing but net and sending the game to overtime at 79.
IMG Academy took its first lead since the first quarter midway through the first overtime period as a George layup made the score 82-81.
Following some back-and-forth action, George came up clutch again, knocking down his second game-tying trey that sent the contest to double OT tied at 85.
After George and Starling traded baskets, the Ascenders went on a 4-0 run for their biggest lead of the night with under three minutes remaining.
After scrapping their way back to within one point, Holloway's 3-pointer from the top of the key in the closing seconds gave La Lumiere the upset victory.

IMG Academy's Keyonte George scored a game-high 40 points Thursday in a 91-88 double overtime loss to No. 5 La Lumiere at the Metro Classic.
Photo by Pete Wright