The Boston Celtics were left to wonder what might have been after a poor third quarter saw them lose Game 2 of the NBA Finals against the Golden State Warriors on Sunday, levelling the series at 1-1.

An underwhelming first half performance saw the Celtics trail by only two points, and after their incredible fourth quarter showing in Game 1, the hope for Boston was they could finish strongly again and take a commanding 2-0 lead.

However, after finding themselves trailing by 23 points by the time the final quarter arrived, they had left themselves far too much to do.

Celtics coach Ime Udoka blamed the amount of turnovers, saying after the 107-88 defeat at Chase Center: "That's been an ongoing theme in the playoffs so far. We've turned over the ball. Take teams out of scoring against us in the half court, give them some baskets.

"But it was more of the same in that third quarter. We had 11 for 18 points in that first half and gave up five or six more in that quarter. Kind of blew it open, and that hampered our offense, as well."

Jayson Tatum - who top-scored for the Celtics with 28 points, though ended the game with a minus-36, which is the worst plus-minus of the 24-year-old's career - agreed with Udoka on turnovers, but also pointed to the general sloppiness at the start of the third-quarter that saw the Warriors pull away.

"I think tonight, turnovers, and I think sometimes letting our offense affect how we defend, kind of was a little stagnant in the third quarter," Tatum said.

"I feel like it translated on the defensive end, and they got going and hitting shots and things like that."

Boston have now been outscored by at least 14 points on four occasions in the third quarter during this year's playoffs, and guard Derrick White also expressed his frustration at the increasing trend of losing the game just after half-time.

"Yeah, it's definitely frustrating," he said. "I mean, we've talked about it pretty much the whole postseason. It's easy to talk about, but we've got to go out there and change something.

"That was a big quarter for them and really a quarter that put us away."