The Philadelphia 76ers held off a late surge by the Toronto Raptors to clinch a 94-89 victory and tie their Eastern Conference semi-final series at one game apiece.

Bidding to snap a 14-game losing streak in Toronto, the Sixers built up a 19-point lead midway through the first half to put themselves firmly in the driving seat.

But the Raptors clawed their way back into contention, cutting their deficit to just one point in the third period and again with 46.7 seconds remaining in the fourth.

A clutch two-pointer from Joel Embiid on the Sixers' ensuing possession helped restore a three-point advantage for the side, before Tobias Harris converted a pair of free throws to seal the victory.

Jimmy Butler also starred, scoring 12 of his 30 points in the final quarter to lead the Sixers to a first win in Canada since November 2012.

Nikola Jokic notched up 37 points as the Denver Nuggets defeated the Portland Trail Blazers 121-113 in the first game of their Western Conference semi-final series.

After a closely-matched first half, Denver surged ahead in the third quarter, opening up a 10-point lead after the first five minutes.

Portland got to within five points in the fourth quarter, but the Nuggets once again eased away after responding with an 8-0 run, holding on to the advantage for the rest of the game.

Damian Lillard finished with 39 points for the Trail Blazers, while CJ McCollum was held to just 16 points on 7-of-17 shooting from the field.