MILWAUKEE -- Devin Williams strode to the mound with a runner aboard and the Brewers locked in a seventh-inning tie. It was his first appearance as the team’s primary setup man in the wake of Monday’s Trade Deadline. Williams struck out the first Pirates hitter he faced with a changeup.

After a walk, Williams ended the inning by getting a groundout with another changeup.

When Williams returned to the mound to pitch the eighth, he struck out all three men he faced.

Changeup. Fastball. Back to the changeup.

Over and over, Williams has baffled hitters with his stuff, particularly his top offspeed offering, during a breakout season that may have peaked Monday, when he recorded five huge outs to earn the win in the Brewers’ 6-5 victory over the Pirates at Miller Park.

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After Williams preserved the tie through the seventh and eighth, Milwaukee emptied its bench to scratch out a run in the bottom of the eighth, taking the lead on Orlando Arcia’s pinch-hit, two-out, two-strike, tiebreaking RBI single.

Before Williams’ third Major League victory went in the books, Josh Hader bounced back from a bout of wildness two nights earlier to deliver his eighth save. When he did -- striking out all three Pirates hitters he faced with sliders -- the Brewers had secured a win on a bullpen day that began with Brent Suter on the mound.

And the Crew did it without David Phelps, one of the key relievers who had worked late innings when Milwaukee was tied or had a lead. Phelps was traded to Philadelphia for three prospects on Monday afternoon.

“It's kind of the two-headed monster right now,” Brewers outfielder Ben Gamel said of Williams and Hader. “Obviously, seeing ‘Phelpsy’ go today wasn't great, but with those two guys on the mound, I like our chances every time.”

Before, it was Phelps and Williams sharing the bridge to Hader. Now, Williams stands to serve in a more prominent role -- to the extent a Craig Counsell-led club has roles. How Williams has done it so far is no secret.

It’s the changeup.

Suter spoke several weeks ago about trying to adopt the pitch himself. He and Williams have worked on it at length, using a puck-like tool that helps the thrower recognize when he properly pronates the wrist to apply the right spin, almost like a screwball.

Williams developed his changeup as a kid in St. Louis when he tried to make friends miss while playing catch, just to mess with them. The pitch feels so unnatural, Suter said, as to be nearly impossible to replicate. And yet, Williams has executed it again and again -- 122 times this season, according to Statcast -- and has yet to give up a hit on the pitch.

Including four of the six batters Williams faced Monday, he has ended 33 plate appearances with a changeup. Opponents are 0-for-31 with 21 strikeouts in those instances.

Oh, and Williams also throws a four-seam fastball that has averaged 96.4 mph this season, touching 98.5 mph.

“He’s a special, special guy,” Hader said. “Every time seeing him on the mound, it’s something. You just have to be all eyes. You’ve just got to sit down and watch it and just enjoy what he’s doing.”

“And he's such a good kid,” Suter said. “I've known him since he got drafted and in the Minor Leagues. He had a tough [Tommy John] surgery like I did, but he was in an even worse spot in the Minor Leagues and had to come back from that. And just what he's overcome in his life, battling adversity and coming up here and just really showing out with his stuff and his approach and his mentality. It's been awesome.”

Williams was the Brewers’ top Draft pick in 2013, when they didn’t have a first-round selection and used their second-round pick on him. He underwent Tommy John in '17 and missed that entire season. He returned to the mound in ‘18, then played in the All-Star Futures Game and made his big league debut in ‘19.

This year, Williams has cemented himself as a reliable, high-leverage reliever, posting a 0.64 ERA over 14 innings spanning 13 appearances. It made Brewers president of baseball operations David Stearns comfortable capitalizing on trade interest in Phelps, even though Milwaukee, now 16-18, is one game out of a playoff spot.

The Brewers will need someone to step into Phelps’ role alongside Williams. It could be another homegrown, hard-throwing right-hander, Drew Rasmussen. Maybe Freddy Peralta. Both were among the five relievers who filled a gap in Milwaukee’s starting rotation on Monday.

“Very early in Summer Camp, I just saw a difference in Devin in just his eyes,” Brewers pitching coach Chris Hook said. “Even last year, when he got to the big leagues and kind of came out of nowhere -- no big league camp -- and kind of like skyrocketed himself through the Minor Leagues. ...

“He believes that he belongs here, and even more so this year in Summer Camp, I could just see it in his eyes, like, 'Hey, I am ready for this. I am ready for anything.' And he's gone out there and proved that.”