CINCINNATI -- Third baseman Todd Frazier's double down the left field line with two outs in the 10th inning drove home Chris Heisey with the winning run, lifting the Cincinnati Reds to a 4-3 victory over the first-place Milwaukee Brewers on Sunday in the finale of a four-game series at Great American Ball Park.
Second baseman Scooter Gennett and left fielder Khris Davis homered for Milwaukee (21-11).
Catcher Brayan Pena and second baseman Brandon Phillips homered for Cincinnati (15-16).
Left-hander Tyler Thornburg (3-1) took the loss. Sam LeCure (1-1) earned the victory.
Brewers starter Kyle Lohse, who spent two seasons in Cincinnati, held his former team to two earned runs and eight hits in 6 1/3 innings. He walked one and struck out two.
Reds starter Alfredo Simon, who was filling Mat Latos' spot in the starting rotation, didn't have his best command on Sunday but he gave the Reds a chance to rally.
Simon allowed three runs and five hits in seven innings, walked one and did not strike out a batter. His previous low this season for strikeouts was three.
Gennett started the scoring with a solo home run, his second, to right field to put the Brewers ahead 1-0 in the first inning.
Milwaukee scored its second run on a two-out RBI single by catcher Jonathan Lucroy. Gomez, who had doubled, scored to put the Brewers ahead 2-0.
Pena got a run back for Cincinnati when he launched his fourth home run 456 feet to right field on the first pitch from Lohse in the third cutting the Reds' deficit to 2-1.
Davis' fourth home run gave the Brewers a 3-1 lead in the fourth.
In the bottom half, second baseman Brandon Phillips doubled and later scored on Todd Frazier's sacrifice fly to make the score 3-2.
Cincinnati loaded the bases in the sixth. But Frazier lined into a double play to end the inning. It was indicative of the afternoon for the Reds, who had five line-drive outs against Lohse.
The Reds had runners on second and third in the seventh but left-hander Will Smith replaced Lohse and retired the final two batters to end the threat.
Phillips' first home run since April 5 came off right-hander Brandon Kintzler and tied the score 3-3 in the eighth.
Cincinnati had runners on second and third with two outs in the ninth, but left-hander Zach Duke fanned Skip Schumaker to end the inning.
Milwaukee stranded runners at second and third in the 10th.
NOTES: Brewers RHP Kyle Lohse made his 23rd career start at Great American Ball Park. ... Reds RF Jay Bruce was scratched from Sunday's starting lineup with left knee soreness. Chris Heisey replaced him. Bruce pinch-hit in the seventh. ... C Brayan Pena left Sunday's game with a leg injury after going first to third in the seventh. ... The Reds begin two-game series against the Red Sox on Tuesday at Fenway Park. "They're the world champs, that's a big enough problem," said Reds manager Bryan Price. "They're very, very good." ... The Brewers return to Miller Park for a nine-game homestand beginning Monday against Arizona. ... Reds CF Billy Hamilton was out of the lineup for a third consecutive game with sprained knuckles suffered while making a diving catch in the first inning of Thursday's game. He entered Sunday's game as a pinch runner. ... Cincinnati's Flying Pig Marathon was held Sunday morning with approximately 20,000 participants hoping to cross the finish line just outside Great American Ball Park.