Celtics work overtime vs. the Grizzlies

“It’s felt like we’ve been on the road for a while,’’ said Pierce. “You get mental fatigue. Especially on a Saturday night when you should be at home watching the Pacquiao fight. That’s what I’m more disappointed at, because I’ve got the fight on DVR.’’

The Celtics had kept the Grizzlies at arm’s length for most of the night, even though they had to go shot for shot to do it. Rudy Gay hit a big one with 7.3 seconds left in regulation, banking in a 6-foot runner over Pierce to tie it at 99. Pierce had a chance to end it but with Gay’s 6-foot-8-inch frame stretched in front of him, he couldn’t get off his long jumper before the buzzer.

Memphis forced Boston to play its third overtime game in 11 days, but on the last day of a weeklong swing, the Celtics pulled out a 116-110 win.

After shooting 53.4 percent on the night, the Grizzlies fired blanks in the extra frame, while the Celtics hit a steady stream of big shots (4 of 6 in OT).

They went 3-1 on their first extended road trip of the season, also handing losses to the Thunder and the Heat. With playoff contenders scattered throughout their first 10 games, the stretch was tough enough. Playing six of them on the road, however, and letting three of them go to overtime made it that much more taxing on a veteran team that’s had to deal with its share of injuries in the early going.

“It’s been difficult, man,’’ Pierce said. “We’ve been tested with some great teams here on the road. Three overtime games. Being on the road all week, and being injured. Not even being healthy. We were just trying to get through the stretch.’’

“It’s been grueling, but mentally it’s been good for us,’’ Celtics coach Doc Rivers said. “We’re winning these games and down the road it’ll help us somewhere. I don’t know where. The great thing is we have rest after this.’’