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Dontrelle Willis couldn't get his forearm to loosen up during his pregame warmup. It got worse as the pitches — and the runs — started to pile up.

San Diego scored four runs in the third inning off the ailing Willis, who left in the middle of the rally, and the Padres avoided a sweep with a 7-3 victory over the Cincinnati Reds on Sunday.

Willis (0-3) left during the four-run rally, shaking and flexing his pitching hand. He'll be examined again on Monday.

The Reds had won four in a row, one shy of their season high. They couldn't overcome Willis' injury-shortened outing.

"I felt some discomfort warming up," Willis said. "I told (pitching coach) Bryan Price that I didn't feel too good, but I'm a competitor, and you're never going to feel 100 percent."

Manager Dusty Baker checked with Willis after the third inning to see how the forearm was feeling.

"He said he was OK, so I sent him back out there," Baker said. "It's one of those things you can't anticipate. It's wide open as to what the problem is. It's unfortunate, because he was throwing the ball well."

A day after the Reds hit seven homers, they were held to four hits, including Jay Bruce's three-run shot off Wade LeBlanc (1-2).

James Darnell had a pair of run-scoring singles for the Padres. Orlando Hudson also tripled home a run.

San Diego dropped the first two in the series, including a 13-1 loss on Saturday night that featured seven Reds homers, equaling the most ever off a Padres pitching staff. A few hours later, San Diego's staff did an about-face.

LeBlanc had only one bad moment. He walked the first two batters in the fourth, then gave up Bruce's fourth homer in his last five games. Bruce also had a three-run homer that won the series opener on Friday and two-run shot on Saturday night.

"It's one of those things," said Bruce, who was the NL's player of the month in May with 12 homers. "When you're good, you're good. When you're not, you're not. I don't want to use age, but hopefully, the experience will come with time and I'll learn what it takes to minimize the funks."

Willis, trying to revive his career in Cincinnati, was the victim of blown saves in three of his first six starts. This time, his arm did him in.

Willis lost his touch in the third inning, when he walked two and threw a pair of wild pitches, one of them letting in a run. After back-to-back RBI singles by Logan Forsythe and Darnell made it 4-0, Baker and a trainer visited Willis on the mound.

After a brief discussion, Willis headed for the dugout, shaking and flexing his left hand.

"This is the first time my arm felt like this," Willis said. "At this point in my career, it's kind of shocking. I think I'll be OK."

Hudson tripled home a run in the seventh off Jose Arredondo, and Darnell singled home another in the eighth off Nick Masset. Jason Bartlett added an RBI single in the ninth off Aroldis Chapman.

LeBlanc finally got a win during his fifth stint with the Padres this year, giving up two hits in six innings. He was called up most recently on Aug. 8. He beat the Reds on April 24 last season at Great American Ball Park, going six innings during a 5-0 win.

NOTES: The Padres called up RH reliever Pat Neshek from Triple-A Tucson and optioned OF Blake Tekotte to the minors. Neshek begins his fourth stint with the Padres this season. ... The Padres completed their road trip with a 6-4 mark. They return home for three games against the Mets and four against Florida. RHP Aaron Harang will try to extend his streak of solid starts — 6-1 with a 3.27 ERA in his last 12 games. ... The Reds are off Monday before starting a nine-game trip to Washington, Pittsburgh and Florida. RHP Mike Leake will start on Tuesday in Washington, trying to become the Reds' first 11-game winner.