The reigning MVP extended his streak of 30-point games to 17 by halftime, pouring in 36 points over the first two quarters to put Houston on top, The Associated Press reported.
It's the longest such streak since Wilt Chamberlain had 20 straight games of at least 30 points in 1964.
It's the franchise-record 14th time Harden has scored 40 this season and the eighth time in his last 11 games. It's the third time he's topped 50 points this season and the 12th time in his career. He surpassed his previous season best of 54 against Washington and fell just shy of the career-high and club-record 60 points he scored last January against Orlando.
After his huge first half, the Grizzlies double-teamed Harden on most every possession in the first few minutes of the third quarter and he didn't score again until there were about five minutes left in the period. That basket was the start of an 11-0 run capped by a three-pointer from Harden that pushed the Rockets' lead to 76-60 with about 3.5 minutes remaining in the third.
Garrett Temple and Mike Conley scored 14 each for the Grizzlies, who lost for the eighth time in nine games.
Harden's big game came on a night when the Rockets were without three starters, as center Clint Capela joined Chris Paul and Eric Gordon on the injured list after he hurt his right thumb Sunday night.
A night after scoring 38 points in a loss to Orlando despite going one-for-17 from three-point range, Harden made his first two triples and finished six-of-15. It's the 13th time in the last 14 games that he's drained at least five after his NBA-record streak of 12 straight ended with his cold shooting performance against the Magic.
Harden made 15-of-17 free throws and had nine rebounds, two assists and two steals.
He crashed to the court making a three as he was fouled by Green to give him 52 points with just under five minutes remaining. Harden completed the four-point play to make it 103-85.
Harden went to the bench to a standing ovation with 3:35 remaining and Houston ahead 107-85.