WINSLOW — Needing a big win to bolster their playoff chances, the Waterville girls couldn’t have played defense any better in the first half on Tuesday night against Winslow.

But Heather Kervin, Devin Fitzgibbons and Alyssa Wood made sure Winslow’s offense got back to speed in the second half, combining for 19 points after the break as the Black Raiders earned a 31-22 victory.

Winslow led 7-3 midway through the first quarter but did not score again the rest of the first half. Waterville, playing much of the half without star Colleen O’Donnell (foul trouble), led 12-7 at halftime.

“We didn’t play together,” Winslow coach Lindsey Welch said of the first half. “We didn’t play as a fist. That’s what I told them: The second half, we played as a fist, and we played as one.”

Several times in the first half, Welch pleaded with her players to work the ball inside. So what did the Raiders do to start the third quarter? Fitzgibbons hit a 3-pointer, Kervin buried a jumper just inside the three-point line, and Wood knocked down a three to give Winslow a 15-12 lead. This all came before Waterville had a field goal attempt in the second half.

“We did talk about pounding the ball inside,” Welch said. “But they were starting to double-team, triple-team down in the post. We said, ‘If we have a wide-open shot, we’ve got to take it and crash the boards.’”

After that, Waterville (7-7) clamped down on defense for the rest of the quarter. Purple Panthers coach Rob Rodrigue felt confident enough to sit O’Donnell for the first four minutes of the second half. At the end of the third quarter, despite having only three field goals to that point, Waterville trailed only 15-13.

“Those other kids did a great job,” Rodrigue said.

Winslow (12-4) worked back inside in the fourth quarter, led by freshman Kervin. In the fourth quarter, Kervin scored seven of her game-high 11 points and grabbed five rebounds. That helped the Raiders shake off back-to-back threes by Waterville’s Fotini Shanos, and turn a 19-19 game into a 27-19 Winslow lead with two minutes left.

For the game, Waterville shot a strong 4 for 12 (33 percent) on 3-pointers, but only 2 of 14 inside the arc. The total is only 26 shots, and only four of those were by O’Donnell.

“We do take pride in our defense,” Welch said. “Sarah Wildes and Delaney Wood step up game in and game out. We give them the challenge of, ‘Are you ready to guard their best player?’ And they accept the challenge. Those two did a phenomenal job.”

“They did a great job stopping dribble-penetration,” Rodrigue said. “We didn’t adjust great (with) our movement off the ball always. They outworked us in the second half.”

Waterville entered the day 13th in Eastern B, a class in which 13 teams make the postseason. The Purple Panthers have four games remaining, but the only one that would likely secure a playoff spot is on Saturday against Oceanside.

“This certainly would have been a big one, and Oceanside’s a big one,” Rodrigue said. “We’ve got four winnable games. I think we’ve got to get three out of four to be certain that we’re going to get a spot. That’s been a goal from day one, is to get in.”

Matt DiFilippo — 861-9243mdifilippo@centralmaine.comTwitter: @Matt_DiFilippo