BOSTON -- The Philadelphia 76ers invaded TD Garden on Sunday looking to make some noise in Game 1 of their Round 1 series with the Boston Celtics. Despite not having Joel Embiid, the Sixers were looking to make some noise and make the heavily favored Celtics sweat in the series-opener.

Instead, the Celtics jumped on them early and earned a 123-91 win to put the Sixers in a hole early. Philadelphia was led by Tyrese Maxey with 21 points and eight assists, Paul George had 17 points and four rebounds, and VJ Edgecombe had 13 points. Kelly Oubre Jr. added 10 points and seven rebounds, and Justin Edwards added seven and six rebounds.

Here are the three biggest takeaways following the loss:

The Sixers generated some good looks from beyond the arc, but had a tough time converting on those opportunities on Sunday. When facing a team like the Celtics that relies so much on their 3-point shot, the Sixers are going to have to convert on those looks as the series continues. To knock down only four triples on the day is not going to get it done, especially on the road. Even the 23 attempts compared to 44 for Boston isn’t going to be enough. The Sixers have to be able to  generate more 3-point looks and match up with this team.

"We know they’re gonna shoot 3s…they got up 44 tonight," said Maxey. "We got up 23. I mean, that’s the game right there, man. They made 16. We made four. That’s 12 more 3s than what we made, and yeah. The score reflected that."

The Sixers knew what they had to contend with in this contest, and in this series overall. The challenge is to slow down both Jayson Tatum and Jaylen Brown on their drives to the basket. Of course, that’s easier said than done, but Philadelphia did a poor job of keeping Tatum out of the paint in this one. Tatum had 25 points, but he shot just 1-for-7 from deep as he was living in the mid-range and in the paint. It was a defensive effort that cannot be accepted in a playoff setting.

"He just did a good job of getting downhill," coach Nick Nurse said. "We just were caught in not very good help positions with him, which just can't happen. I mean, he got to some space, and we can't let him do that. That's the biggest thing."

The Celtics made sure they wouldn’t get beaten by Philadelphia’s star backcourt to start this series. They swarmed both of them and made life miserable as the young guards were not able to find much of a rhythm. On top of that, Boston was able to leave them both open from beyond the 3-point line as neither Maxey or Edgecombe was able to convert on their open opportunities. For the Sixers to have any chance at evening this series up on Tuesday, they will need both guards to bounce back.

Well, I think that they need to kind of let this one go. I think they had some opportunities. It's not like there wasn't some shots that they were taking that—we kind of like a lot of those, right? I think both of them had some, you know, some pull ups in the 15, 14, 12-foot range that they're going to hit most of the time, and just didn't seem to be able to get most of those going. I didn't really like our lack of 3-point shooting, but our lack of 3-point attempts. I thought, once we started, and got cold a little bit. I thought we were turning some down, and we just can't do that. We just got to keep playing every possession like a new one. Not worrying about what happened in some of the older ones.

This article originally appeared on Sixers Wire: 3 biggest takeaways for Sixers following Game 1 loss to Celtics