Marion had 12 points in the first half and Nowitzki added 11 while the Mavericks built a 15-point lead behind 53-percent shooting, including 6 of 8 from 3-point range. Marion and Nowitzki combined to make 14 of 21 shots for the game.
"Being aggressive and just picking my shots," said Marion, who had a season high for the second straight game after scoring 19 in an overtime win at Sacramento on Thursday. "I have been really trying to get my teammates going and in the process get myself going."
Collison put the Mavericks ahead for good with a first-quarter layup that started a 17-4 run for a 30-18 lead early in the second quarter. The Mavericks, who have lost eight games by 20 points, led by double digits the rest of the game.
Nowitzki's second 3-pointer early in the second half was followed by Kaman's streak of eight straight points, capped by a reverse layup that put Dallas ahead 65-45 with 8:12 left in the third.
With Dallas leading by 26 to start the fourth quarter, Gay, Zach Randolph and Marc Gasol were all on the bench in another bad loss in Texas for the Grizzlies. Memphis was beaten by 25 at Houston last month.
Randolph, who entered the game leading the NBA with 24 double-doubles, had six points and four rebounds.
NOTES: Memphis coach Lionel Hollins reiterated comments from a day earlier that he'd like to keep the Grizzlies together with Gay's name consistently turning up in trade rumors. The trade deadline is Feb. 21. Hollins says the Grizzlies are "legitimate contenders." ''That's usually when you're trying to get there, you win a lot of games but you don't do well against the contenders. You might win one or two. But we've been able to compete with every last one of them," Hollins said. Memphis beat division-leading San Antonio in overtime on Friday. ... The Mavericks snapped an NBA record-tying 10-game losing streak in overtime games with Thursday's 117-112 win at Sacramento. ... The Mavericks had nine turnovers, ending Memphis' NBA-best streak of 138 straight games of forcing at least 10 turnovers.