Despite stepping onto the mound at 10 a.m. Saturday at Campanelli Stadium, BC High senior pitcher Mike Vasil was locked in. The Eagles ace went the distance as BC High knocked off Xaverian, 8-1, in a Super 8 elimination game in Brockton, the second complete game Vasil has posted in the tournament.

“Warming up in the bullpen, it’s a 10 o’clock game, the energy might be down,’’ Vasil said. “I was just thinking get ground balls, get outs.’’

BC High (15-8) survived to take on Braintree (16-7) on Sunday in the fourth round of the tournament, while Xaverian (14-9) saw its season end.

Vasil allowed 11 hits, but held the Hawks to just one run.

“The first three innings they had three two-out hits,’’ Vasil said. “I was just trying to be scatter hits, hit my spots, and I threw my changeup today a lot more than I ever have, so that was a key part in getting them off balance.’’

The Eagles piled on six runs in the fourth inning, giving Vasil all the breathing room he needed. Junior Dave Driscoll and senior Tim Keohane each knocked in two runs in the frame, while junior Bobby DeMeo and Vasil chipped in with RBIs.

Vasil’s RBI double ended Xaverian starter Dan Chapski’s day, who was roughed up for seven runs in 3⅔ innings.

BC High junior John MacDonald drove in the last Eagles run in the sixth, while Xaverian junior Kyle Sylvester broke Vasil’s shutout with an RBI single in the seventh.

“I’ve been frustrated because even the guys that watch batting practice say, ‘Why can’t we hit the ball like this in ballgames?’ ’’ BC High coach Norm Walsh said. “Today obviously we put that together, so hopefully we can keep it rolling.’’

Super 8

St. John’s Shrewsbury 4, St. John’s Prep 3 — After putting up two runs in the top of the ninth to take a 3-2 lead, St. John’s Prep was three outs away from winning the Super 8 semifinal at Campanelli Stadium. Junior ace Casey Bussone came in to close it out for Prep, but Shrewsbury had other plans. Senior Jack Gardner tied the game with an RBI double, and senior Jack Fields delivered a bloop single to right field to score Gardner and complete the walkoff comeback.

“[Bussone] was just throwing cheese, we were late on him,’’ Fields said. “I got a fastball I could handle, shot it the other way.’’

The Pioneers (22-3) locked up a place in the Super 8 final, while the Eagles (18-6) await the winner of BC High-Braintree semifinal.

The score was 1-1 through seven innings before the teams traded leads in the last two frames. Shrewsbury went ahead in the bottom of the eighth on an RBI single from senior David Turco, but Prep got two in the ninth to go ahead.

Junior Andrew Dembowski and senior Tyler MacGregor knocked in runs off sophomore Nick McDonald before the Pioneers won it in the bottom of the ninth.

“We knew we needed to pick up Nick,’’ Field said. “We knew we had the offense to do it.’’

Instead of folding after losing the lead, Shrewsbury came back to earn a gritty win and come within one win of the Division 1A championship.

“We still have work to do,’’ Pioneers coach Charles Eppinger said. “We certainly aren’t done yet, so we’ve got to go win one more game.’’

Division 1 North

Lowell 4, Lexington 1 — Lowell has seen its share of ups and downs this season. But on Saturday at LeLacheur Park in the sectional final, it proved to everyone why the Merrimack Valley Conference powerhouse was in Super 8 contention all year.

Three pitchers combined to toss a one-hitter and the fifth-seeded Red Raiders used a three-run sixth to break a tie and defeat third-seed Lexington to win the program’s first sectional title since 2012.

Lowell (17-7) will face the Division 1 South winner next week.

“For these guys, in their mind, I think they thought they were the team to beat,’’ said Lowell coach Danny Graham. “But we want bigger than the North sectional title.’’

Lowell junior starter Matt Draper struggled a bit with his control, hitting the leadoff batter in three of the four innings he began. But was able to settle down and limit the Minutemen to one run, when junior Nico Frelick slid home and knocked the ball loose to tie the game in the bottom of the third.

The score was 1-1 until sophomore Edgar Velazquez led off the sixth with a single. Senior Henry Funaro singled to put runners on the corners with nobody out. After Funaro stole second, Lexington (18-7) elected to intentionally walk senior Alex Cruz to face senior Dan Smith, who drove a two-run double into the right-field gap. Two batters later, senior Marc Beland smacked a run-scoring hit to left field.

“We have been waiting for years to get to a big game late in the season and we’re finally there,’’ said Smith.

Senior Dalton Quinn got the win for the Red Raiders, tossing three hitless innings and striking out one.

Division 2 North

Danvers 7, Gloucester 1 — For the third straight year, Danvers ended the night at LeLacheur Park with its coronation as king of Division 2 North.

Seniors Jordan DeDonato (2 for 3, two RBIs) and Max Paul (2 for 3, RBI) led the way for the third-seeded Falcons (20-4).

Division 4 North

Lowell Catholic 5, Manchester Essex 1 — Three months ago, Lowell Catholic sophomore Alex­ Graves scored the winning goal in the Division 2 state hockey championship game.

On Saturday at LeLacheur Park in Lowell, Graves pitched 4⅔ scoreless innings to help propel the second-seed Crusaders past the sectional’s top seed. Sophomore Kyle DeRoma was 2 for 3 with two RBIs as Lowell Catholic (19-4) earned a return trip to the state semifinals.

“I knew I had to close it out for my team,’’ said Graves, who struck out five and only walked one on five hits.

“I am a real competitive person, and I love playing sports. Hockey — that goal I scored — it helped me out here. It gave me confidence.’’

Like it has all tournament, Lowell Catholic came out swinging.

Sophomore David Gill worked a leadoff walk against Manchester Essex junior Cosmo Pallazola. Two batters later, junior Zach Gitschier ripped an RBI double over the left fielder’s head.

DeRoma drove in his first run on a single that scored Gitschier, and the Hornets were quickly down, 2-0.

“All we said was, ‘We have got to try and score in the first,’ and we did,’’ said Lowell Catholic coach Matt Stone.

Pallazola didn’t make it out of the first inning before Manchester Essex (19-4) called upon sophomore Harry Painter. The righthander escaped without more damage, but left after throwing one pitch in the second inning with an arm injury.

Junior Mitchell Paccone took the mound and calmed down the Crusader bats. But the righthander found trouble in the sixth inning and was charged with two runs on RBIs from DeRoma and senior Harris Varnum.

Lowell Catholic added an insurance run in the seventh inning on a single by junior Mikas Kulbis-Marino. The only Manchester Essex run was unearned and came on a bases-loaded walk in the second inning.

Globe correspondent Karl Capen contributed from Lowell.