PITTSBURGH -- Andrew McCutchen homered and reached base four times and the Pittsburgh Pirates beat the Chicago Cubs 4-2 at rainy PNC Park on Wednesday night.
Pittsburgh pounded Cubs starter Jason Hammel (6-4) for 11 hits in five innings, snapping his streaks of 14 1-3 innings without allowing a run and 52 innings without allowing a homer when McCutchen hit his 10th in the first.
Brandon Cumpton (2-2) pitched five effective innings for the Pirates, who have taken two of the first three games of the series with their NL Central rivals.
Luis Valbuena continued his hot hitting with three hits for last-place Chicago, which has lost three of four after a season-best five-game winning streak.
The game's first pitch was delayed 1 hour, 38 minutes because of a severe thunderstorm that began sweeping through downtown Pittsburgh about an hour before the scheduled start time. Rain fell again during the sixth inning.
The Pirates' Gregory Polanco went 1 for 5 with an RBI groundout a day after his much-hyped major league debut Tuesday.
Making his sixth start of the season and fourth since being given a regular rotation spot, Cumpton allowed two runs on five hits and two walks with five strikeouts. Justin Wilson, Tony Watson, Mark Melancon and Jason Grilli followed with a hitless inning each.
Grilli earned his 10th save of the season during what was his 400th career appearance.
Hammel had won two previous starts against the Pirates this season and entered Wednesday with the second-best WHIP in the majors (0.88).
Hammel, though, allowed 14 baserunners Wednesday. He was spared a worse line by some poor baserunning by Pittsburgh, which hit into two peculiar double plays and had another runner thrown out at third during the seventh inning after Hammel was out of the game.
With a runner on, McCutchen's home run landed just beyond the reach of Cubs left fielder Chris Coghlan, who lunged over the short wall and into the first row. McCutchen, who has a seven-game hitting streak, has 12 extra-base hits in 10 games this month.
The Pirates' Starling Marte had two hits -- including an RBI single in the fifth inning -- but also was thrown out on the basepaths for the third time in two games when he was picked off third following a Travis Snider pop-up behind home plate in the fifth.
The Cubs briefly tied the game at 2 in the second when John Baker's single drove in Valbuena and Nate Schierholtz scored on a groundout.
Valbuena entered with the second-best batting average and on-base percentage in the NL over the previous 21 games. He had two singles and a double.
Notes: Before the game, the Pirates places LHP Francisco Liriano on the disabled list because of a strained left oblique that caused him to leave his start Tuesday in the fourth inning. . The Cubs on Wednesday announced they signed their first-round draft pick, Indiana University catcher/outfielder Kyle Schwarber. Schwarber, the No. 4 overall selection, will report to the organization's short-season Class A affiliate in Boise, Idaho. . Pirates 2B Josh Harrison was removed from the game for a pinch hitter during the third inning because of discomfort in his left ankle. . A fireworks display -- from the nearby annual Pittsburgh arts festival -- rumbled PNC Park for several minutes during the fourth inning. . Pittsburgh's Thursday scheduled starter, RHP Edionson Volquez, is 5-0 in his career against the Cubs. Chicago's probable starter, RHP Jeff Samardzija, has a 1.90 ERA in 71 career innings against the Pirates, including seven shutout innings on opening day at PNC Park.