Olivera homered, doubled and drove in four runs and Perez pitched seven strong innings to help Atlanta end its 12-game losing streak, beating the Philadelphia Phillies 7-2 on Monday night.
"I'm just happy I could contribute and help the club win," Olivera said through an interpreter. "I feel that it builds more confidence, and the more we get going, I'll start feeling better. All in all I'm just happy we were able to get the win."
Olivera, the centerpiece acquisition of the Braves' three-team deal with the Dodgers and Marlins in July, entered 2 for 15 in five big league games. He struck out swinging badly in his first two at-bats.
"They were horrible pitches to swing at," Olivera said. "I wasn't focused. I focused a little better on the next few at-bats after that."
Perez (5-6) had been 0-6 with a 9.50 ERA over his last seven games.
The rookie earned his first victory since June 20, giving up two runs and six hits while striking out seven.
"For once all my pitches were working, and I was locating," Perez, who didn't walk anybody, said through an interpreter. "I felt really good out there."
Atlanta, which stopped its worst skid since 1988, also had lost 13 straight on the road since defeating the Phillies on Aug. 2.
"It's been a real tough time getting `W's," Braves manager Fredi Gonzalez said. "What stuck out like a sore thumb was Williams not walking anybody."
Aaron Harang (5-15) leads the majors in losses. He is 1-12 with a 6.33 ERA over his last 17 starts.
"They know I'm going to throw strikes," Harang said. "That's what I do. They came out swinging."
Brian Bogusevic homered for the Phillies, who have lost four straight and 11 of 14.
"He crushed that ball," Phillies interim manager Pete Mackanin said.
Freeman hit a two-run homer, his 16th, in the first. The Braves began the day with a majors-low 83 home runs.
Olivera's two-run double in the fourth highlighted a three-run inning that made it 5-1. He hit a two-run homer in the ninth.
Bogusevic, called up Friday from Triple-A Lehigh Valley, homered as a pinch-hitter in the fifth in his first at-bat in the big leagues since 2013.
The crowd of 15,125 was the smallest in the 12-year history of Citizens Bank Park. Once a regular sellout, attendance has dropped sharply at Phillies games in the last two seasons as the team's losses have mounted.
"It's really different," Mackanin said. "Put it this way, it's more fun (with a big crowd). You've got to win (to) pack the house."
GOOD LUCK CHARM
In an attempt to end the losing streak, Gonzalez turned to backup C Ryan Lavarnway to bring the lineup card to the umpire before the first pitch.
"It was definitely a superstition thing," Gonzalez said. "And he's going to do it tomorrow also."
NICK FOR TWO
Nick Markakis, playing in his 1,500th game, hit two doubles. He ranks fourth in the majors with 45 multi-hit games this year.
Braves: Olivera returned to the lineup after sitting out Sunday's game at Washington with a bruised left foot.
Phillies: C Cameron Rupp was back in the lineup. He missed two games after getting hit in the arm by a pitch.
Phillies rookie RHP Aaron Nola (5-2, 4.02) tries to rebound from his worst outing when he starts Tuesday night against RHP Ryan Weber, who will make his major league debut. Nola gave up a career-worst six runs and nine hits in four innings of a 9-4 loss at the Mets last Wednesday.
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