Pedro Alvarez hit a three-run homer to cap a five-run seventh inning and Jason Grilli retired Emilio Bonifacio on a bases-loaded grounder to end the game, giving the Pittsburgh Pirates a 5-4 victory over the Cubs on Thursday.
The Pirates trailed 4-0 heading into the seventh, but two big drives changed things.
Pinch hitter Travis Snider cut the deficit in half with a two-run homer off Brian Schlitter. Alvarez put Pittsburgh ahead with his three-run drive against James Russell (0-1), his third homer in two games.
Chicago threatened in the bottom of the ninth before Grilli retired Bonifacio on a grounder to first. The Pirates took two of three at Wrigley Field.
That gave the Pirates their third series win -- the most for them to start the season since the 1992 team took its first six.
Gerrit Cole (2-0) struck out 10 in six innings. He also allowed four runs, three of them earned.
Tony Watson worked a perfect seventh. Mark Melancon retired the side in the eighth before things got tense against Grilli in the ninth.
Grilli gave up a leadoff walk to pinch hitter Ryan Sweeney and a single to Starlin Castro, putting runners on first and second. Grilli then struck out Luis Valbuena and Welington Castillo before Darwin Barney walked to load the bases.
Bonifacio, who came into the game with a .500 average after going 19 for 38, ended it with that grounder to first baseman Travis Ishikawa, giving Grilli his third save in four chances.
Chicago's Travis Wood sailed through six-plus innings, allowing four hits, striking out nine and walking three. He left to cheers with a four-run lead after the Neil Walker led off the seventh with a double.
Snider, batting for Clint Barnes, then drove a two-run homer to the shrubs in center off Schlitter, cutting it to 4-2. Schlitter also gave up a single to Starling Marte and walked Andrew McCutchen with two out before Alvarez drove the first pitch from Russell off the roof of a party suite beyond the bushes in center. The home run was Alvarez's fifth on the season.
With a 1-0 lead going into the fourth, the Cubs took advantage of a wild pitch and an apparent blocking-the-plate call while scoring three more runs.
Anthony Rizzo and Nate Schierholtz singled leading off. Castro drove an RBI single through the left side with one out, and Schierholtz came home on a wild pitch to Mike Olt.
The lead grew to 4-0 when Castro was called safe at home on Castillo's two-out single even though the throw from Marte in left field beat him by several steps. The problem was Sanchez appeared to be blocking the plate, and under a new rule, catchers have to give runners a clear path.
NOTES: The Pirates said top pitching prospect Jameson Taillon had Tommy John surgery on his right elbow on Wednesday. He is expected to miss 12 to 18 months. ... The Cubs open a three-game series at St. Louis on Friday, and manager Rick Renteria was asked if he sees the Cardinals as a model for what Chicago's trying to do. "It's hard to argue with a club, an organization, that's had success over the years," he said. "You've got to see what it is that they do and don't do. You take things from every organization in baseball, but certainly, they've had a tremendous amount of success over the last few years -- and over their existence."