FOX CHAPEL — One set had already slipped from Seneca Valley’s grasp.

The Raiders weren’t about to let it happen again.

After missing out on a chance to sweep Norwin in Tuesday’s WPIAL Class AAA girls volleyball quarterfinal playoff, the Raiders found themselves in a back-and-forth affair in the fourth set.

Norwin’s Maria Ferragonio dropped a kill to even the score at 22 and hand possession back to the Knights, but SV soon answered to take a slim lead.

Then with Madison McDonough behind the service line, Kate Davis and Madeline Poirier both tallied kills to close out a 25-18, 25-21, 24-26, 25-22 victory at Fox Chapel High School.

The Raiders (17-3) will face unbeaten North Allegheny, a 3-1 winner over Armstrong, in Thursday’s semifinal round at a site and time to be determined.

Davis is one of six reserves Raiders’ coach Karen Martini uses on a regular basis. The latter’s kill late in the fourth set was pivotal to the match’s outcome.

“Our bench is so talented,” said junior hitter Tatum Poirier, who ended the night with 13 kills, including five in the final set. “We have confidence that those girls can step into a big match and contribute.”

SV’s rebound followed a third set that saw the team lose despite holding a 24-21 lead. Norwin’s Taylor Sabol and Nicole Novak both had kills and Taylor Ingel a key block as the Knights scored the set’s final five points.

“We finally started to play,” said Norwin coach Mary Ellen Ferragonio. “We started out slow, but got the jitters out and got comfortable.”

Despite allowing Norwin to make things interesting, the Raiders remained composed, knowing a trip to the WPIAL’s final four was still there for the taking.

“Two years ago, we were in this same position against Norwin,” said Martini. “It was a quarterfinal and we won the first two sets, then lost three straight. A lot of the girls on this year’s team were involved with that. They were ready for a fourth game.”

“Sometimes, it’s mentally tough,” said Tatum Poirier of playing an unexpected fourth set, “but we’ve been through it so many times before. We’re used to it.”

Norwin, the Section 1 champion, had leads in the first (12-8) and second (7-5) sets, only to have Seneca Valley grab control down the stretch.

“We started ball-handling really well,” said Martini. “When we do that, it allows us to do so many things.”

Maria Alfano had 12 kills and five blocks for the Raiders. Melissa Carter added 11 kills and three blocks and Madeline Poirier 11 kills.

The Raiders will now prepare to play North Allegheny for the third time this season. SV is one of only three teams to take a set from the Tigers in 2015. The Raiders fell to NA 3-0 Sept. 10 and 3-1 Oct. 6.