PITTSBURGH -- Getting one home run from the Pittsburgh Pirates is a rarity this season, so imagine the surprise when they hit two Saturday night.
Only the San Francisco Giants have hit fewer than the Pirates' 36 home runs this season. It was the first time since May 25 that Pittsburgh had a multihomer game and only the eighth instance in 62 games this season.
"We don't hit many home runs, we're more of a gap-to-gap team," said Sanchez, who leads the National League with 22 doubles. "It just came at the right time. Hopefully, we can keep it going."
Sanchez hit his second career slam in the fourth inning to give the Pirates an 8-2 lead. LaRoche homered in the second when the Pirates scored four times off Armando Galarraga (3-7).
Sanchez's grand slam was his fifth homer of the season. LaRoche, the Pirates cleanup hitter, hit his eighth homer, but his first since May 21.
"That's what we need to do," Pirates manager John Russell said. "We're not going to score nine every game, but we need to be more productive when we have opportunities. We did that tonight."
Duke has pitched at least six innings in all but one of his 13 starts this year.
After giving up a one-out homer to Raburn in the fifth, Duke settled down and retired his final 11 batters. He struck out three and walked one.
Duke admittedly was relaxed pitching with such a big cushion provided by Sanchez's slam.
"It definitely calms you down," Duke said. "I pitched to contact. When you do that, hopefully you can get quick outs so you can rest your bullpen."
Galarraga, winless in his past nine starts, allowed four runs and eight hits in two-plus innings. He was lifted after giving up back-to-back singles to open the third.
"My sinker was bad, my slider, too," Galarraga said. "I felt like when I made a good pitch, they hit it anyway. My command was really bad."
Nate Robertson pitched out of trouble to keep the Tigers within 4-2, but it was a different outcome when the Pirates loaded the bases against him in the fourth.
After the Tigers got a force at home for the second out, Sanchez homered over the left-field wall.
"I tried to go away, and it cut in," Robertson said. "I don't know if the ball had a scuff on it, but it cut back over the plate."
Raburn homered in the fifth to pull the Tigers within 8-3. McCutchen had an RBI single for the Pirates in the sixth.
Galarraga opened the season 3-0 with a 1.85 ERA in four starts. Since then, he has gone 0-7 with two no-decisions and a 7.54 ERA.
Tigers manager Jim Leyland said he's concerned about his starter.
"When you're trying to throw here and it goes there, and when you try to throw there and it goes here, that's not good," Leyland said.
Leyland gave CF Curtis Granderson a day off for the first time this year. Granderson, batting .315 with 11 RBI in his previous 19 games, will return to the lineup Sunday, Leyland said. Raburn replaced Granderson in center. ... Russell sat RF Brandon Moss and will give him Sunday off as well. Moss is in an 0-for-15 slide that has dropped his batting average to .243. ... Pirates RHP Charlie Morton may have his start Tuesday in Minnesota pushed back a day because of tightness in his hamstring. Morton's status will be determined Sunday. If he cannot pitch, LHP Paul Maholm will move up a day in the rotation. ... To mark the 100-year anniversary of the 1909 World Series victory against the Tigers, the Pirates honored 13 members of championship teams, including former manager Chuck Tanner. ... Four former Pirates managers were in attendance: Tanner (1977-85), Leyland (1986-96), Gene Lamont (1997-2000) and Lloyd McClendon (2001-05). Lamont and McClendon are on Leyland's staff.