Boston’s Gordon Hayward went 16 for 16 from 2-point range on Tuesday in Cleveland. The last player to do so? Wilt Chamberlain. Tony Dejak/Associated Press

CLEVELAND — It was slightly more than two years ago when Boston swingman Gordon Hayward suffered a horrific leg injury on Opening Night in Cleveland, leaving the floor on a stretcher, altering the Celtics’ season and pausing his rise into bona fide NBA All-Star.

Back in the same building on Tuesday night, Hayward looked like his preinjury self. Maybe even better.

Hayward punctuated the young season by putting on a short-range clinic in leading the Celtics to their fifth straight win, the first of a three-game trip. Boston plays at Charlotte Thursday night.

Hayward tied his career high with a 39-point performance that included a record in 2-point field goals with a 17-for-20 performance. All three of his misses were from beyond the arc, where he made 1 of 4. He also had eight assists and seven rebounds.

When Hayward drove, and defenders remained glued to his shooters, Hayward beat the Cavs with a series of floaters and short pull-ups. When the Cavs finally came at him, Hayward picked them apart with lobs to his rollers, Daniel Theis and Robert Williams.

“He’s got that great ability to hit the floater, but he can also stop and hit the fade – he does that all the time in practice,” said Boston Coach Brad Stevens. “Today that was where he was living, mostly. I think he only had one mid-range. Everything else for the most part was inside, 6-to-8 feet maybe. It was the right read to take those shots, and when they came at him he dumped it off for dunks.”

Perhaps the most audacious stat of all was Hayward’s 16-for-16 proficiency inside the arc. According to Dick Lipe, the stat guru, the last player to go 16 for 16 dates back to well before the 3-point era, to Wilt Chamberlain.

“Seems like a pointless stat to me,” Hayward said, smiling. “Good night, maybe I shouldn’t have shot those 3’s then, just kept shooting the 2’s.”

Last year, Hayward’s feel-good nights only came in spurts. In six games this season, he is averaging 20.3 points and shooting 56.5 percent from the floor.

“There’s been more opportunities this year, we’re running some things I’m more comfortable doing,” he said. “As long as we’re attacking, and I’m not overthinking the game, not hesitating, we should be fine. Have to continue to attack. I’m not going to score every night. As long as I get in the paint and make the right read we should be fine.

“There’s more responsibility with more opportunities, and I have to continue to make the right reads there.”

MARCUS SMART missed the last game of the regular season and the first seven of the playoffs last spring to a torn oblique muscle, so the Celtics’ guard had every right to obsess after falling to the floor in the third quarter Tuesday night after taking a shot to the same area.

But he was guarding Kevin Love. That meant getting up, and getting out to resume covering the 6-foot-10 Love – the latest assignment in Smart’s very prideful determination to guard anyone and everyone.

“Oh my goodness. He’s a warrior, man. I’m super happy he’s my teammate. I love being on the floor with him – he just gives me so much energy,” Kemba Walker said. “The things he does are so amazing. For him to guard K-Love the way he did, especially down the stretch. He’s a beast and he wants those challenges.”

And he wants those assignments without help.

“My preparation for the game – I scout it, I’ve played against Kevin Love for a long time now,” said Smart. “I’m such a great defender and believe in myself, so it’s about pride at that point. I call the double team off any chance I get. I can take care of myself.”

That includes getting up off the floor when his sore oblique tells him to stay down.

“The exact same one. It knocked the wind out of me, was scary, because I thought the same thing was about to happen. But the oblique is stronger and can withstand hits like that,” he said. “I had to (get up). At that moment it’s not about me, it’s about the team.”