PHILADELPHIA -- Everybody knows the story of the Phillies’ bullpen over the past few years.

It was one of frustration and heartbreak.

But something is happening with the bullpen this year, particularly since the end of May. Not only is it pitching well; it is dominating. It is making up for the losses of Bryce Harper and Jean Segura by keeping the Phillies in games when they’re behind and holding onto narrow leads when they’re ahead.

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Philadelphia’s bullpen allowed one run in five innings in Thursday’s 5-3 victory over the Nationals at Citizens Bank Park. It is a huge reason why the Phillies hold a share of the third NL Wild Card spot as they open a nine-game road trip on Friday in St. Louis.

“Everybody is throwing the ball really well down there,” Phillies ace Zack Wheeler said. “Give them credit. They keep grinding. They know the narrative the past couple years, but they’re pushing against it and doing well. They’re making everybody be quiet, which is a good thing.”

From Opening Day through May 31, the bullpen was 8-11 with a 4.17 ERA. Opponents had a .731 OPS against it. It ranked seventh in baseball in strikeout rate (25.3 percent), but 29th in walk rate (11.1 percent). It ranked 18th with a 1.1 WAR, according to FanGraphs. But from June 1 through Wednesday, it was 9-3 with a 3.11 ERA. Opponents had a .581 OPS against it. It ranked fourth in strikeout rate (27.1 percent) and 17th in walk rate (9.5 percent). It is tied for second in baseball with a 1.5 WAR.

Phillies relievers are limiting hard contact better as well, as evidenced by a 42.6 percent hard-hit rate and 89.4 mph average exit velocity through May compared to 32.3 percent and 88.6 mph since June 1. They are behind in the count less, too: 30.1 percent of pitches through May vs. 28.8 percent since June 1. And they are ahead in the count more: 26 percent of pitches through May vs. 27.2 percent of pitches since June 1.

An extra strike here and there every night makes a huge difference.

“I think once you get a bullpen hot and things start clicking the right way, it’s a lot easier to keep things going rather than if it’s the opposite,” left-hander Brad Hand said. “If you start giving up some leads, starting to give up some runs, it can snowball. We’ve just got to keep attacking hitters and keep getting outs.”

Phillies interim manager Rob Thomson is pushing the right buttons along the way as his pitchers have settled into their roles. Hand and Seranthony Domínguez have shared closing duties over the past few weeks. Thomson interchanges them depending on how the opposing lineup stacks up in the eighth and ninth innings. José Alvarado, Corey Knebel and Andrew Bellatti are pitching well in high-leverage situations in the middle-to-late innings.

Nick Nelson has been an effective long man for much of the season. He pitched two scoreless innings Thursday. Alvarado followed; he struck out Juan Soto, Josh Bell and Nelson Cruz in order in the seventh. After being optioned to Triple-A Lehigh Valley at the end of May, Alvarado has struck out 17 and walked four in nine innings in his last 11 appearances.

Alvarado threw seven sinkers Thursday that averaged 100.7 mph. He threw seven cutters that averaged 95.5 mph.

Most important: he threw nine strikes.

“His stuff is electric,” Hand said.

Hand allowed one run in the eighth, but Domínguez pitched a scoreless ninth to earn his third save. The 27-year-old righty has been absolutely dominant this season and should receive NL All-Star consideration, even though that often seems to go to relievers with the most saves.

“We were just talking about that,” Wheeler said about Domínguez’s All-Star case. “He doesn’t get as much credit as he should, but he’s faced the toughest parts of the lineup, whether it’s the eighth or ninth.”

But think back to the past few years. So many times the Phillies entered the late innings down a run or two, then -- poof -- a small deficit ballooned into a big one, ruining any chance of a comeback. Then, of course, there was the seemingly endless run of blown saves.

It’s not happening this year.

“Everybody has kind of calmed down a little bit,” Thomson said. “They know where they’re going to pitch and what part of the game they’re going to pitch in. I think that helps them out. They’ve responded.”