随着芝加哥落后 8-7 有两个出局和第七个基地加载, 施温德尔从替补队员尼克·米尔斯（Nick Mears）的一记弧线球击中中锋的看台，扭转了局面.
Duffy also had three hits and Jason Heyward also went deep as the Cubs won their sixth straight. He had just one homer before Sunday.
Schwindel, who took over at first base in late July after Anthony Rizzo was traded, has gone deep in three straight games and six of seven. It was his first career grand slam and 10th homer with Chicago.
Bryan Reynolds hit a grand slam and had four hits, and Yoshi Tsutsugo also went deep for Pittsburgh, which has dropped sixth straight. The three grand slams tied a major league record.
Adbert Alzolay (5-13) pitched a scoreless 1 2/3 innings and Rowan Wick got the final six outs for his third save. Sam Howard (2-4) allowed two runs in one third of an inning for the loss.
Tsutsugo got the homer barrage started with a solo blast in the first to make it 1-0.
Duffy and Heyward led off the second with back-to-back homers to put the Cubs on top.
Reynolds’ grand slam — the first of his career — in the third gave Pittsburgh a 5-2 edge, but Chicago answered with five in the bottom half on an RBI single by Ian Happ and Duffy’s slam for a 7-5 铅.
Pittsburgh tied it with two runs in the fifth. Jacob Stallings had a sacrifice fly and Ben Gamel, who was hit by a pitch, scored on a wild pitch by Manny Rodriguez with two outs.
The Pirates took advantage of more Cubs miscues in the sixth to take an 8-7 铅. Reynolds singled with one out, Colin Moran followed with a walk and both advanced on a passed ball. Reynolds scored on an infield single by Stallings.
Gamel appeared to save the game for the Pirates in the seventh when he made a diving catch on the warning track in left on a liner by pinch hitter Willson Contreras with runners on first and second for the second out. But Howard walked Rafael Ortega to load the bases and bring Schwindel to the plate.
海盗: RHP JT Brubaker and RHP Duane Underwood Jr. were both placed on the 10-day injured list before the game with shoulder inflammation. RHP Kyle Keller and RHP Shea Spitzbarth were recalled from Triple-A Indianapolis.
小熊: The team said Sunday LHP Brad Wieck is doing well and recovering in Chicago after undergoing a heart procedure on Aug. 31. He has been sidelined since early July with an irregular heartbeat. The 29-year-old underwent a similar procedure during spring training last year. Wieck had a 0.00 他在 15 游戏 (17 局) for Chicago this season. There is no timetable for his return.
海盗: RHP Bryse Wilson (2-6, 4.61 时代) starts the opener of a three-game home series against the Tigers on Monday. LHP Tarik Skubal (8-12, 4.26) goes for Detroit.
小熊: LHP Justin Steele (3-2, 3.48 时代) pitches the opener of a three-games series against the Reds on Monday. RHP Sonny Gray (7-6, 3.89) takes the mound for Cincinnati.