Trailing 27-26 at halftime, Braintree outscored Sharon 23-8 in the third quarter and won, 65-47. It was the second game of the 27th annual Dudley Davenport Hoop Classic.
"I have no answers, and no idea what happened in the second half. I don't think I've ever seen anything like that happen," Sharon head coach Bruce Jackman said.
"Granted, they did a good job defensively. But we certainly did not step it up at all. We did not match their intensity."
The two-day tournament ends tonight. Sharon (5-13) will play Natick in the consolation game at 6 p.m. Braintree (9-10) faces Taunton in the championship game at 7:30 p.m..
Taunton defeated Natick, 74-73, in overtime in the opener.
Braintree has won three of the last five Davenports. New Bedford broke the Wamps' two-year winning streak last season. Sharon last won the tourney in 2008.
Sunday, sophomore guards Brian Mukasa and James Fritzson led Sharon with 13 and 11 points, respectively. Junior forward Brian Lawrence added 9 points.
Braintree was led by junior forward Steven Lee, who had 18 points, 10 in the second half. Senior guard Ashton Williams added 13, and senior forward Justin Fein had 12 for the Wamps.
"The advantage we had over (Sharon) was inside, on the boards, and we finally took advantage of that a little bit," Braintree head coach Robert Crook said.
"We started to shut them down going to the basket, and we were able to turn that into some fast-break opportunities as well."
One early stop by Sharon drew applause.
Senior tri-captain and center Sam D'Arcy recorded his 86th blocked shot of the season with 7:28 left in the first half, breaking the prior record, set in 2000.