(Photo credit: Charles LeClaire-Imagn Images)

Spencer Horwitz's grand slam backed up a quality start from Bailey Falter and helped the host Pittsburgh Pirates finish off a three-game sweep of the frontrunning Detroit Tigers with a 6-1 victory on Wednesday afternoon.

Horwitz belted his third home run of the season and first career grand slam in the second inning off Detroit prospect Troy Melton (0-1), who made his major league debut.

The 416-foot blast, which came with two outs, gave Pittsburgh a 5-0 lead and put the Pirates on course for their fourth series sweep of the season and 10th win in their past 13 home games. Horwitz finished 7-for-12 with seven RBIs in the series.

The Tigers lost their third in a row and for the ninth time in their past 10 games. They were swept for the third time this season and second time in their past three series.

Melton's rough day ended after five innings in which he allowed six runs on seven hits, including two home runs, walking two and striking out seven.

Andrew McCutchen had the other home run in the bottom of the first -- his ninth of the season -- to put Pittsburgh ahead 1-0.

Oneil Cruz had two hits and an RBI and stole two bases, bringing his season total to 33. Bryan Reynolds also continued his torrid hitting with two hits, including his 21st double of the season.

Detroit produced its lone run in the top of the seventh when Falter (7-5) allowed a double to Spencer Torkelson and a single to Matt Vierling with one out.

But Falter was sharp beyond that, delivering a bounce-back performance in which he struck out eight with no walks, and allowed the lone run on four hits in seven innings.

Zach McKinstry, Wenceel Perez and Colt Keith each had a hit for the Tigers, who have scored only nine runs in six games since the All-Star break, with five of those coming in Tuesday's 8-5 loss.

To make room for Melton on the active and 40-man rosters, the Tigers placed ace Tarik Skubal on the paternity list and designated center fielder Brewer Hicklen for assignment.

--Field Level Media