Marcus Smart said "I bet on myself 110 per cent of the time" after making a crucial late block in the Boston Celtics' Game 7 triumph over the Toronto Raptors in the Eastern Conference semi-finals.

With a little under a minute remaining of the deciding rubber in Orlando, Smart made a critical intervention against Norman Powell that ended the Raptors' best chance of tying the game.

Just a few days ago it was Powell who nailed a one-on-one lay-up against the same opponent to level a thrilling series, which the Celtics finally saw out with their 92-87 victory on Friday.

"As soon as Norman caught the ball, instantly I remembered last game," Smart said.

"In my mind I was just telling myself, 'He has to dunk it. I'm not gonna give a foul. I'm just gonna meet him up top and see who wins that battle.'

"I bet on myself 110 per cent of the time. I'm first-team All-Defense for a reason and I believe in that wholeheartedly."

Smart often gets overlooked by the higher scorers in the Celtics' team and it was Jayson Tatum who led the way with 29 points, 12 rebounds and seven assists.

But team-mate Kemba Walker paid tribute to Smart's work, which he often feels goes under the radar.

"That block was so special," Walker said. "It was unreal. That's why he's first-team All-Defense. 

"He shows it night in and night out. He made so many huge plays tonight. A lot of the things he does just go unnoticed.

"But that kid, he's special, man. He's on a different level at that end of the basketball court."

The Celtics' reward is a showdown with the Miami Heat in the Eastern Conference Finals, two sides who have a long-term history in the playoffs.

The rivalry stretches to the boardroom with Celtics president Danny Ainge and Heat counterpart Pat Riley having bad blood that spans four decades.

Celtics coach Brad Stevens believes their experience against the Raptors, whose hopes of retaining the NBA title are now over, should stand them in good stead for an altogether different task.

"We should definitely be hardened," he said. "We should definitely have a lot more in our toolbox to go back to. We have to get ready for a different, more unique team now in Miami."

Raptors star Kyle Lowry admitted it was a difficult defeat for the team to swallow, saying: "Man, it was a tough game to lose. But they won. Tip your hats to them. They have a chance to go on and play against Miami and get to the championship."

Raptors head coach Nick Nurse added: "They gave everything they had. Special team."