SOUTH DEERFIELD - A career-best effort by Cassidy Stankowski and mostly dominant overall play by the Frontier Regional girls volleyball team were enough to overcome an incredibly gutsy defensive performance by Mahar Regional Monday night.

The top-seeded Red Hawks improved their record to 19-0, but it didn't come easily in the Western Massachusetts Division 3 Tournament quarterfinals at Goodnow Gymnasium.

The eighth-seeded Senators (12-9) fought off a pre-match injury and actually won a game before Frontier's height and depth were simply too much in its 25-10, 24-26, 25-8, 25-13 victory.

The four-time defending sectional champion Red Hawks advanced to the semifinals Thursday at home against No. 4 Monument Mountain (17-4) which defeated No. 12 Lenox 3-0 in another quarterfinal Monday.

Mahar coach Sarah Woodward, whose squad was already missing a middle hitter due to injury, lost starting middle hitter Elise Powers to a sprained ankle during warm-ups, a crippling blow to a team severely lacking in height.

Frontier took advantage of that early, as Stankowski (career-high 30 kills) registered 10 kills alone in the opener. The freshman phenom unleashed a string of four consecutive putaways to give the hosts a 5-1 lead.

"Cassidy is a great player," said Woodward. "I've known her since she started playing volleyball. She's a smart player. We moved our defense around because of her, and tried to move some people around to block her a little better. She's got a great career ahead of her."

The lead grew to 7-1 before the teams began trading points. At 17-9, Stankowski ripped another powerful spike into the open floor to send Marie Wheeler to the service line. She served four straight points, helped by a Stankowski kill and a Kelsey Abramson tip to extend the lead to 21-9. After exchanging points, Stankowski finished the game with two powerful jump serves.

Frontier jumped out to another 5-1 advantage in Game 2, but when the score reached 8-3, something appeared to click with the Senators. After a side out at 8-4, Kendra Killian served for four points to pull Mahar even for the first time in the match.

Frontier tried to seize the momentum back and managed to build a 14-10 lead despite some sloppy play in the front row, but some outstanding defensive play by Sam Parker, Amanda Johnson and Jackie Paulilus helped the Senators tie the game at 15-15 and again at 20-20.

Johnson was in the midst of a seven-point service run that put Mahar ahead for the first time, and they ran it to 24-20 before Angelica Perfido's tip snapped the run at 24-21. Courtney Parent reeled off three points Frontier to tie the game at 24-24 before two unforced Red Hawk errors at the net closed it out and left match tied at 1-1.

Frontier unleashed a flurry of winners in Game 3 to take control. With the score tied at 5-5 and Wheeler at the service line, the Red Hawks ripped off 10 straight points to take command 15-5. Stankowski kept the Senator defense off balance with a combination of tips and kills, while Parent (23 assists) and Wheeler (17 assists) were key in keeping the offense running smoothly during the entire game.

Kendra Ouimette went to the line for another five-point stretch late in the game before Holly DeWitt finished it off with a blast that deflected off a Mahar block and dropped in for the final point.

Game 4 was a close affair until it was 12-9, when Frontier got a side out and Wheeler went to the line and served for three points and a 16-9 lead. After exchanging a few points, Ouimette took over at 18-13 and served out the match.

"After the first game, it seemed like things were going our way," said Red Hawks head coach Sean MacDonald. "Then it was a combination of us making a lot of unforced errors and them digging almost everything we could throw at them.

"This was the best I've seen Mahar play in a while, at least against us. My hat's off to them. They really played well, especially with one of their starters down."