Pirates 15, Brewers 5: Russell Martin went 3-for-3 with four RBIs and three runs scored as host Pittsburgh pounded nemesis Kyle Lohse and visiting Milwaukee in the opener of a three-game set.

Jordy Mercer homered and drove in three runs and Andrew McCutchen added a solo shot and two RBIs as the Pirates rode an eight-run sixth inning to halt a string of six straight losses to Lohse. Jose Tabata also had two hits and two RBIs to help Brandon Cumpton (1-2) earned his first win of the season despite giving up three runs and eight hits in 5 1/3 innings.

Lohse (7-2) had his seven-game overall winning streak snapped, failing to record an out in the sixth inning and getting knocked around for a season-high eight runs on nine hits. Khris Davis drove in a pair of runs, Aramis Ramirez had an RBI single among his two hits and Carlos Gomez added two hits and scored twice for the Brewers, who lost for only the third time in the last 11 meetings against the Pirates.

McCutchen doubled in a run in the first and scored on Martin's single before launching a solo shot in the third to stake the Pirates to a 3-0 lead, but Milwaukee scored twice in the fourth on Ramirez's RBI single and Davis' sacrifice fly. Mercer homered to lead off the fifth and Neil Walker added an RBI single later in the inning before Davis' run-scoring single in the sixth cut the deficit to 5-3.

Pittsburgh open the bottom of the sixth with three straight singles, including one by Tabata to chase Lohse in favor of Tyler Thornburg, who yielded Mercer's RBI single and walked two batters to plate another run. After a two-out walk forced in another run, Martin cleared the bases with a double off the top of the wall in center before Tabata capped the uprising with a run-scoring single for a 13-3 edge.

GAME NOTEBOOK: The Pirates parlayed five singles, a double and four walks in the sixth for their first eight-run inning since Aug. 12, 2012, against San Diego. ... Lohse, who beat Pittsburgh in back-to-back starts in April, allowed his highest run total in 45 starts with Milwaukee to fall to 11-3 lifetime versus the Pirates. ... Harrison's first-inning single extended his hitting streak to nine games.