PHILADELPHIA -- The thought crossed Zack Wheeler’s mind almost immediately after another Phillies loss on Saturday night: he needed to pitch well on Sunday.

“It kind of comes down to me,” he told himself.

Wheeler delivered in a 6-2 victory over the Red Sox at Citizens Bank Park. He tied a career high with 12 strikeouts and allowed one run on three hits and one walk in 7 1/3 innings. Wheeler almost single-handedly snapped the Phillies’ four-game losing streak on an afternoon in which they played without Bryce Harper, J.T. Realmuto and Didi Gregorius.

• Box score

“I didn’t put any more pressure on myself when I was out there,” Wheeler said. “I just kind of pitched my game and did my thing. But I knew it was a big game for us. We needed to get back on that winning track going into Miami. We need to win those games. Just keep that going. Hopefully today starts a new little run for us.”

Wheeler has been on a run since his first start of the season, when he allowed one hit and struck out 10 in seven scoreless innings against the Braves on April 3. He has a 2.38 ERA and a 0.94 WHIP in 10 starts. Wheeler is the first Phillies pitcher to have a sub-2.50 ERA and a sub-1.00 WHIP in the first 10 starts of a season since Roy Halladay in 2011 (2.21 ERA and 0.98 WHIP), according to the Elias Sports Bureau.

Halladay should have won his second consecutive National League Cy Young Award that season, but he fell short to the Dodgers' Clayton Kershaw.

Who knows where Wheeler will end up? But it is easy to make the argument that he has been the Phillies’ best player to this point. He entered the afternoon leading the team with a 2.6 bWAR and a 2.0 fWAR.

“He’s one of the best,” Red Sox manager Alex Cora said.

“There’s a ton of ways to quantify things now,” Phillies right fielder Brad Miller said. “But just the old-fashioned way: you watch him pitch, he seems pretty dominant. Notice it takes the guys a couple swings, a couple times through the order to even be competitive. So I think that was big today, jumping out early and letting him cruise. Because it’s hard to throw a shutout every time. Things are going to happen, but when you’ve got a little cushion, I think he can really go into attack mode.”

Rhys Hoskins had an opposite-field single in the first inning to score Odúbel Herrera to give the Phillies a 1-0 lead. Miller followed two batters later with an opposite-field three-run home run to make it 4-0. Both hits came with two strikes and two outs.

Wheeler retired 17 consecutive batters after he allowed a leadoff single in the first. He leaned on his fastball because he is locating it well and nobody can hit it when he does. The Red Sox missed 41 percent of the fastballs they swung at, which was Wheeler’s best whiff rate of the season.

“I’m just throwing like I normally have,” Wheeler said. “I think my ball is a little more true this year. Maybe the spin rate -- I don’t even pay attention to that stuff -- but maybe that’s up a little bit.”

Wheeler's slider and curveball proved effective as well. He threw only six curveballs, and only two before the seventh inning. But the Red Sox swung at and missed four of them.

“I’ve always had a good feel for the curveball,” he said. “I really haven’t thrown it that much this year, which I guess could be a good thing as the year goes on. Maybe start throwing that a little more later on. Who knows?”

The only blemish on Wheeler’s afternoon: Franchy Cordero crushed a solo home run a projected 474 feet to right field in the eighth inning. It is the longest home run at Citizens Bank Park since Statcast began tracking home run distances in 2015.

But Wheeler and the Phillies can live with that. They needed to feel something positive before they boarded a flight to Miami. Even as poorly as they have played lately, they are 23-24 and only 1 1/2 games behind the Mets for first place in the National League East.

“You’re going to have your days, you’re going to make errors and all that type of stuff,” Wheeler said. “But we’ve had some talks and we’re a good close-knit group of guys. We can talk. I think everybody is on board and hopefully we can get it going and play some clean baseball."