Kevin Garnett tied a season high with 24 points and grabbed nine rebounds as the Boston Celtics rode a strong inside game to a 98-80 victory over the visiting Memphis Grizzlies on Sunday afternoon.

Paul Pierce scored 10 of his 21 points in the fourth quarter to help Boston extend its winning streak to four games.

Reserve forward Chris Wilcox added 12 points and rookie JaJuan Johnson had 10 as the Celtics overcame 20 turnovers in beating a Western Conference opponent for the first time in five attempts this season.

Johnson, seeing his most extensive action of the season, dunked to cap a 7-0 spurt at the outset of the fourth quarter as Boston built a 76-63 lead with 9 1/2 minutes to play and steadily pulled away.

Rudy Gay scored 21 points, including 14 in the third quarter, to keep the Grizzlies within striking range entering the fourth. O.J. Mayo added 15 for Memphis.

The first half featured dueling spurts. Wilcox sparked an 18-4 run to help Boston take a 24-16 first-quarter lead, but Mayo scored nine points to ignite a 16-3 tear to open the second quarter and put the Grizzlies in front 32-27.

The Celtics stormed right back, getting seven points from Pierce in a 16-2 surge to go ahead for good en route to taking a 43-35 edge into halftime.