Despite being shorthanded, the Boston Celtics secured a huge win over the Philadelphia 76ers in game one of their second-round showdown at TD Garden on Monday night.

The home team came into the game without Kyrie Irving, Gordon Hayward and Jaylen Brown but still managed to dominate the Sixers and claim a 117-101 victory to open up the series.

With several of Boston's best offensive players missing, the 76ers were installed as the favourites to advance to the Eastern Conference Finals but as we've seen all season, the Celtics are not a team that can be written off easily.

The win for the C's wasn't a big surprise but the fact that they managed to score 117 points with some of their best scorers out most certainly was.

It was even more impressive as it came against one of the better defensive teams in the league.

Philadelphia ranked among the top 10 in defence but they allowed Boston to shoot 49 percent from three-point range.

Speaking after the game, Joel Embiid was critical of how they defended and took some of the responsibility for that too.

"It starts on defence. I thought I was s---ty. I thought we were all bad tonight," Embiid said, per ESPN's Ian Begley. "That's not who we are, definitely.

"I think when everybody's on, we're the best defensive team in the game. There's a lot of stuff that we game-planned that we didn't execute."

The Celtics drained 17 three-pointers while the Sixers made just 5-of-26 from beyond the arc.

"I thought this was one of our poorer defensive games," head coach Brett Brown said. "I think to look at this game, defensively, offensively, this isn't who we are. This is a very poor game from us."

This was just the second loss in the last 22 games for the Sixers so there shouldn't really be any panic going into game two.

Ben Simmons believes rust played a big part in their struggles as they enjoyed six days off after eliminating the Miami Heat in five games.

Boston, on the other hand, went all the way to a game seven against the Milwaukee Bucks on Saturday and appeared to be in a better rhythm despite just the one day of rest.

"I think they came ready to play and we were very rusty, and we just got smacked multiple times and we didn't react. I think that's what it was," Simmons said.

They usually rely heavily on the three-point shot but they were cold on the night which contributed to the big loss.

Philly will hope to produce a better showing on both ends of the floor in Wednesday night's game two and look to even things up.

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