BOSTON -- On paper, there was every reason to believe the Boston Celtics would easily handle the Orlando Magic on Friday night.

After all, Boston already had a pair of 30-point wins over the Magic this season and Orlando had lost 12 straight games at TD Garden.

As we said, on paper.

On the court, it took Amir Johnson contesting an Elfrid Payton drive in the closing seconds to allow the Celtics to escape with a 117-116 victory that kept them a half-game ahead of the winning Cleveland Cavaliers atop the Eastern Conference.

"I thought Orlando played great tonight and we had to find a way," Celtics coach Brad Stevens said after his team closed out a 5-1 homestand with its 49th win of the season -- a franchise high since 2010-11.

Stevens was answering a question about whether fatigue plays a heavy part in things this time of year, but he said every team in the league is tired.

"If you had real issues with fatigue you don't find a way," he said. "So we had a lot left in the tank."

They needed it, especially in a frenzied finish after Al Horford's two free throws with 1:22 left turned out to be the final points of the night.

The wild scramble at the end led to Payton's drive down the lane. He missed with 2.3 seconds left and Al Horford grabbed the rebound.

"I loved the look. It was a great look. I make that nine out of 10 times," said Payton, who dished out a career-high 15 assists in orchestrating the near-upset.

The Magic, who suffered their second straight heartbreaking defeat, didn't call a timeout after Terrence Ross grabbed a rebound with 12.9 seconds left and handed the ball to Payton.

Isaiah Thomas scored 35 points and dished out seven assists, Jae Crowder scored 18 points, rookie Jaylen Brown had 12 points and nine rebounds and Horford collected 12 points, nine rebounds and six assists.

"Any way we can get a win is what we're looking forward to," Thomas said. "They're a different team. ... They've been playing a lot better since the All-Star break."

Crowder, asked if the team was getting bored with just six games left in the regular season, said, "Boredom? We're trying to win. We ain't bored at all."

Aaron Gordon, a game-time decision because of a sore shoulder, scored 32 points and grabbed 16 rebounds, matching his career high, while Payton dished out a career-best 15 assists to go with 12 points and nine rebounds. Evan Fournier scored 20 points, Ross 17 and Jodie Meeks 13.

"I'm tired of moral victories," said Gordon, whose team fell in overtime to Oklahoma City and Russell Westbrook's historic 57-point triple-double Wednesday night. "No moral victories for us anymore. I know for somebody else on the outside maybe it's positive that we were able to keep up with one of the best teams in the East, if not the best team in the East, but for me it's not just a win. It's a loss."

The Celtics, who trailed by as many as 13 points, improved to 23-0 when leading after three quarters at home.

"It was a crazy finish," said Thomas. "But we kept our composure and got stops when we needed it. That was what was very important tonight, especially toward the end."

As far as the 5-1 homestand, Thomas said, "It was good. We had a tough loss to Milwaukee ... but it was definitely a successful homestand."

Thomas, who set the Celtics' season 3-pointer record Wednesday night, extended another club record with a 3-pointer in his 51st straight game and also recorded his 51st 25-point game and 29th 30-point game. It was also his 67th 20-point game (including 12 straight), one behind Westbrook for the league lead.

NOTES: Celtics G Avery Bradley was out again with a recurrence of the stomach bug that cost him a game earlier on the homestand. He is also doubtful for Sunday's game against the Knicks in New York. "He's not in the hospital, but he's not doing so hot," said coach Brad Stevens. ... Former Celtics F Jeff Green didn't make the trip and missed his fifth straight game with back spasms. ... The Magic are at Brooklyn Saturday night. ... Stevens said he's been in touch with Gonzaga coach Mark Few at the Final Four. "There's no better person than Mark Few. He's a great guy and I'm really happy for him," he said.