"He had to go because that's what we had," manager Charlie Manuel said.
A five-game winning streak crumbled against the last-place Brewers. The lead was surrendered on an uncharacteristic leadoff walk exacerbated by shoddy defense. Milwaukee captured victory in the ninth because lefthander Jeremy Horst was tasked with facing the righthanded heart of the Brewers' lineup.
Mike Adams, signed for $12 million to pitch the eighth, is sidelined by what he called "biceps irritation." Antonio Bastardo and Justin De Fratus were not to be used because of heavy workloads. Jonathan Papelbon was entering only if a save situation emerged.
That made Horst the man.
"That's what it was," Manuel said. "When I looked at it, I figured Horst might have a hard time."
Jean Segura rolled an infield single to shortstop. Ryan Braun pelted one up the middle. And Aramis Ramirez stroked a slider into left for the winning hit.
"I've done it before," Horst said. "If Chuck tells me to go back out there, then he must think I'm the right guy for the job."
This was once a four-run lead for the Phillies with their best pitcher on the mound. The seeds of defeat were planted in the seventh inning. It unraveled rather fast.
Norichika Aoki walked on six pitches. Segura lashed a first-pitch fastball to the right-field corner. Delmon Young, usually removed in the seventh inning for a defensive replacement when the Phillies are ahead, was slow to reach it.
Aoki scored. Young hopped his throw to Freddy Galvis, who fired an unnecessary relay toss home. It skipped past Erik Kratz and bounced to no one. Segura dashed for the plate and caught his finger on Kratz's shinguard but scored the tying run.
Manuel defended Young's presence, saying, "That didn't hurt us at all. That guy hit a triple. That didn't hurt us. He was going to come up the next inning, too, and I was going to let him hit."
When Young batted in the eighth with the go-ahead run at second and one out, he flailed at the first pitch from Burke Badenhop and grounded into a rally-killing double play. That, finally, prompted his removal from the game.
Lee's night finished at 122 pitches, which tied a season high. He entered the day seventh in the National League with a 2.45 ERA. Milwaukee gave him a better challenge than any team in the last month.
Lee was perturbed by his walk to Aoki. He praised Milwaukee's hitters and said the pitch to Segura was well-executed. He expected to take the ball in the seventh.
"I didn't even know how many pitches I threw," Lee said. "I felt good till the very end."
The Brewers stranded three runners on third base in the game's first four innings. Lee constantly made key pitches in tight situations. He threw 73 pitches in the first four innings. A Kratz two-run homer staked Lee to a 4-0 lead in the fourth. Milwaukee countered with two runs in the bottom half of the inning.
Alfredo Figaro, used as a reliever, made his second start of 2013. The Brewers also will ask their bullpen to log all nine innings Saturday. The situation was prime for an extended Phillies run.
Adams' latest injury is of concern. He downplayed the soreness, saying he would need "a couple of days" to rest it and that it was something he experienced in the past. Adams has required two surgeries to his shoulder, most recently one last winter.
The reliever deemphasized a back injury suffered last month and that ultimately required a trip to the disabled list. The biceps problem has afflicted him for a week, he said.
That made this Lee's game, and once he departed a tie game, the path to victory was difficult.
Contact Matt Gelb at email@example.com. Follow on Twitter @magelb.