The Hornets trailed 69-59 after three quarters but behind Mason's shooting went on a 22-2 run to take an 81-71 lead with 4:14 remaining.
At one point Mason had scored nine points in a 17-2 Hornets run. The Rockets missed their first four shots of the quarter and made one of their first 12.
"They did a good job of blocking the paint and really making it tough on us," Lin said. "We didn't do a good job of finding that open man and making that open pass, me included. I'm the point guard and that starts with me."
The Hornets, who were 1-19 when trailing after three quarters, made 10 of their first 13 shots in the fourth quarter. The Rockets' 10 points were the lowest total New Orleans allowed in a quarter this season.
Gordon and Vasquez sat out for much of the fourth quarter and Davis and Lopez did not play in the final period.
Harden was 1 of 4 in the fourth quarter.
Harden scored 15 points to stake the Rockets to a 36-34 halftime lead.
New Orleans made seven of its first 12 shots to take an early lead but struggled from the field the rest of the half. The Hornets led 16-10 midway through the first quarter when Williams gave Austin Rivers, Davis and Gordon a break.
With New Orleans' scoring trio on the bench, the Rockets closed on a 12-2 run to take a 22-18 lead. Harden, who missed his first two shots, made three of his last five to finish the quarter with nine points.
Notes: The Hornets are 10-11 when holding opponents to less than 100 points. . .New Orleans completed a three-game sweep of Texas teams, winning at Dallas this past Saturday and coming home to knock off San Antonio and Houston. . .The Hornets are on a three-game win streak for the first time since last April.