Four Cubs relievers combined for four scoreless innings, with Craig Kimbrel working the ninth for his 10th save. The bullpen has allowed only one unearned run over its last 29 2/3 innings.
Kimbrel gave up a leadoff double to Cole Tucker but retired the next three batters.
Chicago won for the seventh time in nine games and is 14-7 in May. Pittsburgh lost again in its first game back home following a 1-5 road trip.
Both of Pederson’s longballs came off rookie Cody Ponce (0-1), who was recalled from Triple-A Indianapolis earlier in the day to make his first start of season and fourth of his career.
Ponce allowed four runs in five innings while taking the rotation spot of Trevor Cahill, who was placed on the injured list last weekend. The Cubs got nine hits of Ponce, who struck out two and walked one.
Cubs second baseman Nico Hoerner left the game in the sixth inning with a strained left hamstring after going 2 for 3. He was injured when he hit the first base bag awkwardly with his left leg while trying to bunt for a hit.
After Pederson tied the game, the Cubs went ahead in the fifth inning when Javier Baez hit a two-out double and scored on Anthony Rizzo’s single.
The Pirates scored twice in the first inning on a passed ball by rookie C.J. Higgins and an RBI single by Jacob Stallings. Ben Gamel singled in Will Craig, who doubled, in the second inning to make it 3-0.
Gamel went 2 for 2 with a walk before leaving for a pinch hitter in the seventh inning.
Cubs: C Willson Contreras (bruised left wrist) was held out after being hit by a pitch Sunday night at St. Louis. X-rays taken Monday were negative and Contreras participated in batting practice before the game. Higgins started behind the plate. … INF/OF Matt Duffy (low back strain) was placed on the 10-day IL retroactive to Sunday. INF Patrick Wisdom was selected from Triple-A Iowa. RHP Jason Adam was designated for assignment three days after undergoing left ankle surgery.
Pirates: RHP Chad Kuhl (right shoulder discomfort) made a rehab start for Indianapolis on Tuesday night and gave up one run and one hit in 3 1/3 innings against Omaha with four strikeouts and two walks. … Rookie 3B Ke’Bryan Hayes (left wrist sprain) went 3 for 6 with a double and a home run in his two rehab games for Indianapolis.
The Pirates optioned RHP Kyle Keller to Indianapolis to open a roster spot for Ponce. Keller made three relief appearances for Pittsburgh and gave up three runs in 3 1/3 innings.
Cubs RHP Trevor Williams (2-2, 5.97 ERA) starts against rookie Pirates RHP Wil Crowe (0-2, 4.91) on Wednesday night. Williams is 0-1 in two starts this season against the Pirates, who released him last December, and has allowed seven runs in 7 1/3 innings. Crowe will be looking for his first career win in his ninth start and 10th appearance.
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