By Hannah Becker, Globe Correspondent

Undefeated Andover will defend its state championship at the DCU Center in Worcester on Saturday after defeating Braintree, 54-39, in the EMass Division 3 final Tuesday at TD Garden.

“It’s good to win here at the Garden and we just have Saturday to see what we can do,” Andover coach Jim Tildsley said. “I’m very excited, very happy for my kids.”

Andover (26-0) went on an 8-0 run midway through the fourth quarter to take a nine-point lead. Sophomore forward Rebecca Alois began the run with a layup under the basket before senior guard Nicole Boudreau (22 points) took over, netting two three-pointers and two free throws to push the score to 47-36.

“My teammates trust me to step up in those situations,” Boudreau said. “Rebecca helped me out there with a couple of layups and it’s a total team effort.”

Braintree got within six with just over three minutes left, but Andover’s defense was too much down the stretch.

Braintree (22-3) opened a 6-0 lead to start the game. Andover didn’t get on the board until Boudreau hit two free throws at the 3:46 mark of the first quarter. Braintree's fast-paced offense stumped Andover, and Braintree led 13-7 after the first quarter.

“We weren’t playing good defense,” Boudreau said.

Andover climbed back in the second quarter. Senior guard Ally Fazio netted a layup and then a three to give Andover an 18-17 lead midway through the quarter. The teams traded baskets for the rest of the half, and Braintree led, 25-23, at halftime.

Andover increased its defensive pressure in the third quarter and held Braintree to 14 points in the second half. Junior forward Jackie Alois hit a jumper from the baseline to tie the game for Andover with 6:23 left in the third, but Braintree’s Molly Reagan got it right back with a layup of her own at the other end.

“I just thought the second half, defensively, we just played really, really well,” Tildsley said. “We’re talented, but we have a lot of heart out there.”

Andover took its first two-point lead of the game when junior guard Devon Caveney netted a layup and was fouled with 59.8 second left in the third quarter. She hit the free throw and Andover led 31-29.

“Devon struggled in that first quarter, but she played a heck of a second half,” Tildsley said. “And what can you say about those two Alois girls? We just did a really great job rebounding.”

Andover began the fourth on a 4-0 run with baskets from sophomore guard Rebecca Alois from a nifty pass from Boudreau and Caveney. Braintree answered with a basket from Reagan with just over six minutes to play and Andover led 37-36. That was as close as Braintree got, because Andover used an 8-0 run to seal the victory.