CHICAGO - The hard-hit grounder went right to shortstop Starlin Castro, and he made a strong throw to first. It was just too late to get Gregory Polanco.
The play proved costly when Josh Harrison followed with a two-run homer, sending Castro and the Chicago Cubs to a rain-delayed 5-3 loss to the Pittsburgh Pirates on Saturday night.
"It was a bad bounce," Castro said. "I had to turn around. It was really hard, too, and the guy run pretty hard from home plate, that's why I didn't get him."
Jordy Mercer went deep for the second straight day and Andrew McCutchen had a tiebreaking RBI single for Pittsburgh, which had lost four of five. Vance Worley (1-0) pitched into the seventh inning for his first win with the Pirates.
Harrison's fifth homer with two out in the seventh made it 5-2 and came after Polanco was the beneficiary of baseball's replay system. He was originally called out by umpire James Hoye in a close play at first after he hustled down the line on his sharp grounder.
"The play was a hard-hit ball to Starlin, who came up slower than he probably should have," Cubs manager Rick Renteria said. "Polanco is busting his rear end down the line."
The review also extended Polanco's hit streak to 11 games, making him the first NL player to begin his major league career with such a streak since Juan Pierre hit in 16 straight games for Colorado in 2000.
"He looked safe, so you go out and you have your people run the replay," Pirates manager Clint Hurdle said. "As sure as you are, you don't know until you know. It turned out to play very big for us."
Anthony Rizzo hit a two-run homer for Chicago, which had won four of five. Eli Whiteside doubled home Darwin Barney in the seventh.
"The guys keep battling, they keep playing," Renteria said.
The start of the game was delayed for 2 hours, 1 minute while a storm passed through the area.
Rizzo's 15th homer, a drive to the bleachers in right in the fourth, gave the Cubs a 2-1 lead. The big first baseman, making a case for a spot on the NL All-Star team, is batting .318 (27 for 85) with seven homers and 19 RBIs in his last 23 games.
Pittsburgh responded in the fifth. With two outs and runners on first and second, Harrison and McCutchen each singled back up the middle to put the Pirates back in front. Brian Schlitter then replaced Travis Wood with runners on the corners and retired Russell Martin on a bouncer to third for the final out.
Wood (7-6) allowed four hits, walked three and struck out four. The left-hander had won each of his last two starts, including a season-high eight innings of three-hit ball in a 3-0 victory at Philadelphia in his previous outing.
"We got a little wild for a little bit, brought the ball up a little bit where they could find some holes and put some runs on the board," Wood said.
Worley gave up three runs and five hits in 6 2-3 innings. The righty, who was acquired in a March 25 trade with Minnesota, pitched seven shutout innings in his first start of the season last Sunday at Miami.
"Used all his pitches, pounded the strike zone, gave us a real good effort," Hurdle said.
Jared Hughes got the final out of the seventh, Tony Watson tossed a perfect eighth and Mark Melancon struck out the side for his 11th save in 14 chances. It was Melancon's first opportunity since Hurdle announced on Friday he was removing struggling righty Jason Grilli from the closer role.
The Pirates played without speedy outfielder Starling Marte, who left the team to attend to a personal matter in his native Dominican Republic. Jose Tabata got the start in left and went 0 for 3 with a walk.
Hurdle said he thinks Marte will be back in time for Monday night's game at Tampa Bay.
NOTES: Cubs C Welington Castillo (rib injury) went 1 for 5 and drove in a run in his first rehab game with Triple-A Iowa on Friday. "Felt good, and he continues to progress," Renteria said before Saturday's game. ... Cubs RHP Jason Hammel (6-4, 3.02 ERA) faces RHP Brandon Cumpton (2-2, 5.82 ERA) in the series finale on Sunday.