Reds 7, Cubs 3: Todd Frazier belted a two-run homer and Ryan Ludwick added a solo shot in a five-run fourth inning to power host Cincinnati.

Jay Bruce also clubbed a solo homer, his 25th of the year and fourth in five games, as the Reds won for the sixth time in seven games.

Bronson Arroyo (9-7) pitched 6 1/3 innings for the win, giving up three runs on nine hits. He also struck out three and walked three to help Cincinnati improve to 39-21 at home - the best mark in the majors.

Cubs left-hander Travis Wood (4-9) absorbed his sixth straight defeat, getting battered by his former team for seven runs - six earned - and nine hits in five innings.

Luis Valbuena homered and Wood had an RBI single to give the Cubs a 3-1 lead, but the Reds pounded Wood for five runs on six hits - five for extra bases - in the bottom of the fourth to go ahead 6-3.

Ludwick went deep for the fourth time during his nine-game hitting streak - his 23rd homer of the year - and Frazier followed with a two-run blast to put Cincinnati ahead to stay. Zack Cozart added an RBI double and Stubbs had a run-scoring triple in the inning.

Reds closer Aroldis Chapman worked a perfect ninth in a non-save situation and registered his 23rd consecutive scoreless appearance.

GAME NOTEBOOK: Ludwick has hit eight of his 23 homers on the first pitch. ... Valbuena's homer was his fourth of the year and first since June 29. ... Bruce has driven in eight runs during a five-game hitting and RBI streak. ... Wood has surrendered 14 homers in his last eight starts. ... Frazier has six multi-hit games with three homers and nine RBIs in his last eight games. ... The Cubs are working on a long-term contract extension for SS Starlin Castro. Entering Friday's game, Castro, 22, was batting .276 with 12 homers and 58 RBIs. ... The Reds will call up RHP Todd Redmond from Triple-A Louisville to make his major-league debut in the second game of Saturday's doubleheader. It will end Cincinnati's reign as the only team in the majors to have used only five starters this year.