WAREHAM, Mass. — With one loud swing of the bat, Murf Gray turned a tightly contested game into a foregone conclusion.

The Whitecaps and Wareham Gatemen were knotted at 5 in the bottom of the eighth when Gray (Fresno State), Wareham’s third baseman, teed off for a 420-foot three-run blast, giving his team a decisive advantage.

“It’s one pitch, one good swing,” assistant coach Scott Grimes said postgame. “It wasn’t a mishap, a mistake or anything along those lines. It’s just a good swing by them.”

Gray’s homer all but sealed Wareham’s 8-5 win over the Whitecaps on Saturday night at Spillane Field on a foggy night that also saw Brewster manager Jamie Shevchik ejected in the eighth inning.

The contest was a back-and-forth affair throughout. Wareham took an early lead, but Brewster drew level in the fourth. The Gatemen jumped in front again, but the Whitecaps tied it up in the seventh. That was, until Gray delivered the knockout punch.

Facing Brewster starter DJ Primeaux (LSU), Wareham scored its first runs on a wild pitch and RBI double. The first two hitters, Brendan Summerhill (Arizona) and Bobby Boser (South Florida), both singled, then executed a double steal to reach scoring position.

Summerhill scampered home when a Primeaux pitch got past catcher Ryder Helfrick (Arkansas). Jace Rinehart (South Carolina Upstate) drove home Boser later that at-bat, roping an RBI double to left.

Primeaux worked a 1-2-3 second with two strikeouts but ran into trouble in the third. Wareham hit three consecutive singles, the last of them a line drive to left from Rinehart that scored Boser from second.

With runners on second and third later in the frame, the Gatemen scored a fourth run in unorthodox fashion. Primeaux appeared to trip on the mound as he threw a pitch, which bounced in front of the plate.

The umpire appeared to call it a ball initially, but the call was switched to a balk after the umpires convened on the infield grass. Shevchik came out of the dugout to plead his case, but the call stood and Gray — the Wareham runner who had been on third — trotted home.

That was it for Primeaux, who allowed six hits and four runs in his three innings. In his previous 9 1/3 innings this season, Primeaux had allowed just one earned run and five hits. Even after Saturday’s start, Primeaux’s ERA is just 3.65.

Brewster scored its first run in the top of the second. J.D. Rogers (Vanderbilt) singled to center, advancing to second on a groundout and to third on a wild pitch. He scored after a passed ball sailed to the backstop.

Then, the Whitecaps tied things up in the fourth. The first three batters — Helfrick, Daniel Cuvet (Miami) and Dallas Macias (Oregon State) — reached on a hit-by-pitch, single and another hit-by-pitch, respectively. Brody Donay (Florida) drove both Helfrick and Cuvet home with a base hit to center. Drew Faurot (Florida State) drove home Macias with a single two batters later, knotting the score at 4.

Wareham took a 5-4 lead in the bottom half of the fourth on a wild pitch, but Brewster nearly got out of the inning unscathed thanks to an impressive play by Cuvet. After the Gatemen put runners on the corners with nobody out, Michael Lippe (Louisville) tapped a soft grounder to third. The runner on third, Eli Putnam (Davidson), took off for home, and Cuvet rifled a strike to Helfrick to nab him at the plate.

It was a beautifully executed bang-bang play from Cuvet, but the go-ahead run scored a few batters later when catcher Jacob Jarrell (Clemson) scored on the wild pitch with two outs.

Parker Detmers (Louisville), who came in for Primeaux in the fourth, stayed on the mound to toss scoreless frames in the fifth and sixth. In his three innings of work, Detmers allowed just two hits and one run with four strikeouts.

“He did a good job of settling himself down and refocusing himself to get back out on the mound and get in the strike zone,” Grimes said.

Brewster tied things up in the seventh after Cuvet cranked a double to drive home Nick Dumesnil (Cal Baptist), who hit a leadoff single and advanced to second after Helfrick was hit by another pitch.

The RBI hit punctuated another solid night for Cuvet, who stayed hot after his dramatic tying home run Friday night.

“He’s just a good hitter, that’s what it comes down to,” Grimes said. “He can just really hit. He’s got a really good work ethic, day-to-day stuff. He always handles business well.”

Shevchik’s frustration from the third-inning balk bubbled over in the eighth. Reliever Kyle Percival (North Carolina) appeared to strike out Wareham pinch hitter Colby Turner (San Diego State), but the umpires ruled that the third strike had been fouled off by Turner. Convinced Turner had whiffed on the pitch, Shevchik stormed out of the dugout.

After a brief back-and-forth, home plate umpire Joshua Garcia pointed Shevchik to the exits. Turner walked, Boser singled and Gray drove them both home with his home run.