Manteca is officially back in the Sac-Joaquin Section playoffs for a fifth straight year.

This time, the Buffaloes had to sweat it out in a play-in match to get there. They overcame a spirited effort from No. 21-seeded St. Mary’s on Tuesday, 23-25, 25-20, 25-21, 25-27, 15-7.

It was one of six play-ins in the loaded Division II bracket, and this one was the most competitive. Manteca (22-6), seeded 12th, is rewarded with a first-round trip to No. 5 Rio Americano tonight.

“We felt cheated when we got in the play-in,” Manteca middle blocker Chase Cheng said. “We crumbled for a couple games tonight, but we did not want to lose. We just had to go out there and get the win.”

Cheng came up clutch for the Buffs, who let late leads slip away in the first and fourth sets that they controlled, for the most part.

After stealing an emotion-filled fourth game that included a red-card penalty, St. Mary’s (15-15) carried the momentum into the final set and scored the first three points. Cheng scored on a dink that closed Manteca in 6-5, but he was just getting started.

He gave the Buffaloes the lead for good at 8-7 with a kill and followed that with a solo block of St. Mary’s Dylan Neves (15 kills, 10 service points, two aces). Cheng then stuffed Kevin Ross (eight kills, three blocks) and Neves on back-to-back plays to set up match point.

It was fittingly Cheng who closed it out with a thudding spike off a crafty one-handed set from freshman Chandler Harris (39 assists, 10 digs, two kills, four total blocks).

Cheng finished with eight kills and 12 total blocks (six solo).

“I was asking for it,” Cheng said. “Until the third set, I was dealing with leg cramps. In the fifth set, I felt perfectly fine. When my outside tipped it out, I was like, I want the ball now.”

These two teams previously met on the same gym floor back on March 2, but that one played out much differently — a sweep for the host Buffaloes.

That was when Manteca had its best player in third-year outside hitter Jesus Gomez, who recently had season-ending surgery on an injured hand.

“It was so long ago, it’s almost like both teams are so different,” Manteca coach Jen Reis said. “They didn’t have some of their guys the first time, and vice versa for us — we lost a few. At this point in the season, everyone’s better or different, so it was a good test.”

With Gomez done for the season, others have stepped up.

Juniors Dennen Loureiro (14 kills, two aces, 14 service points) and Logan Romriell (eight kills, 16 service points, 10 digs) spearheaded the outside attacks Tuesday, while 6-4 senior middle Rob Hevener (11 kills, four total blocks) and 6-3 junior opposite Donovan Morse (two kills, eight total blocks).

Raclif Figueroa and Raul Carranza led the back-row defense with 11 and eight digs, respectively.

“It’s been an interesting last week and a half to two weeks,” Reis said. “Momentum sometimes is hard to come by, and tonight, when we were rolling, we’d lose it. We had to find a different source, so we had some guys step up in different moments. We had some big blocks, which are momentum changers, and Chase really came through in that fifth set.”

Nicolas Salazar paced the St. Mary’s attack with 14 kills, and the Rams served up 10 aces.

It only gets tougher from there, as the Buffs head to Sacramento next to square off with the Capital Valley Conference champion Rio Americano (16-16) for the first time in boys volleyball.