Mitch Keller tossed shutout ball into the sixth inning and the Pittsburgh Pirates slipped past the San Diego Padres 2-1 on Tuesday night.

Keller (2-3) kept the Padres off balance by mixing his pitches effectively. He allowed two hits over 5 2/3 innings and struck out five.

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Pittsburgh Pirates' Adam Frazier (26) is greeted by teammate Phillip Evans (24) after scoring off an RBI double by Bryan Reynolds during the third inning of a baseball game against the San Diego Padres, Tuesday, May 4, 2021, in San Diego. (AP PhotoGregory Bull)

Mitch Keller tossed shutout ball into the sixth inning and the Pittsburgh Pirates slipped past the San Diego Padres 2-1 on Tuesday night.

San Diego Padres starting pitcher Dinelson Lamet works against a Pittsburgh Pirates batter during the first inning of a baseball game Tuesday, May 4, 2021, in San Diego. (AP PhotoGregory Bull)

Keller also got his first major league hit, a single to right field in the fifth.

Pittsburgh Pirates' Bryan Reynolds hits an RBI double during the third inning of a baseball game against the San Diego Padres, Tuesday, May 4, 2021, in San Diego. (AP PhotoGregory Bull)

The Padres activated right-hander Dinelson Lamet to make the start and he was on a strict pitch count. Lamet left his season debut after just two innings on April 21 with right forearm tightness. He lasted two innings and threw 30 pitches this time, giving up no runs and four hits.

San Diego Padres shortstop Ha-Seong Kim, left, is greeted by teammate second baseman Jake Cronenworth during the second inning of a baseball game against the Pittsburgh PiratesTuesday, May 4, 2021, in San Diego. (AP PhotoGregory Bull)

The Padres scored in the seventh off reliever David Bednar to narrow the gap to 2-1. With one out, Nola singled to drive in Will Myers from second base. Bednar struck out Ha-Seong Kim and retired pinch-hitter Fernando Tatis Jr. on a popup to end the threat.

Pittsburgh Pirates starting pitcher Mitch Keller works against a San Diego Padres batter during the first inning of a baseball game Tuesday, May 4, 2021, in San Diego. (AP PhotoGregory Bull)

Pirates: Placed OF Gregory Polanco on the injured list without giving a reason. “I can’t comment on any of that. He’s on the IL. That’s all I can say,” manager Derek Shelton said.” To take Polanco's roster spot, the Pirates selected OF/INF Hunter Owen, whose first action will be his major league debut.

The right-hander entered with an 8.20 ERA after his first five outings this season.

Pittsburgh Pirates' Adam Frazier (26) is greeted by teammate Phillip Evans (24) after scoring off an RBI double by Bryan Reynolds during the third inning of a baseball game against the San Diego Padres, Tuesday, May 4, 2021, in San Diego. (AP PhotoGregory Bull)

Pittsburgh Pirates' Adam Frazier (26) is greeted by teammate Phillip Evans (24) after scoring off an RBI double by Bryan Reynolds during the third inning of a baseball game against the San Diego Padres, Tuesday, May 4, 2021, in San Diego. (AP PhotoGregory Bull)

Keller also got his first major league hit, a single to right field in the fifth.

Four relievers combined to give up only one run in 3 1/3 innings for the Pirates. Richard Rodriguez earned his fifth save by working a scoreless ninth.

With two outs and the bases empty for San Diego, left fielder Ka’ai Tom made a jumping catch against the wall on a hard smash by Austin Nola that would have gone for extra bases.

San Diego Padres starting pitcher Dinelson Lamet works against a Pittsburgh Pirates batter during the first inning of a baseball game Tuesday, May 4, 2021, in San Diego. (AP PhotoGregory Bull)

San Diego Padres starting pitcher Dinelson Lamet works against a Pittsburgh Pirates batter during the first inning of a baseball game Tuesday, May 4, 2021, in San Diego. (AP PhotoGregory Bull)

The Padres activated right-hander Dinelson Lamet to make the start and he was on a strict pitch count. Lamet left his season debut after just two innings on April 21 with right forearm tightness. He lasted two innings and threw 30 pitches this time, giving up no runs and four hits.

Ryan Weathers (1-1) started the third inning in relief and promptly gave up a run on back-to-back doubles by Adam Frazier and Bryan Reynolds. Weathers got the next three batters to keep it 1-0.

Pittsburgh scratched a run across in the sixth against Keone Kela for a 2-0 lead. With one out, Erik Gonzalez singled and stole second. He was running on a pitch hit by Jacob Stallings to Padres second baseman Jake Cronenworth, who threw to first to attempt to get the second out. But meanwhile, Gonzalez kept running around third and beat the throw home by first baseman Eric Hosmer, who was charged with an error for coming off the bag before the catch.

Pittsburgh Pirates' Bryan Reynolds hits an RBI double during the third inning of a baseball game against the San Diego Padres, Tuesday, May 4, 2021, in San Diego. (AP PhotoGregory Bull)

Pittsburgh Pirates' Bryan Reynolds hits an RBI double during the third inning of a baseball game against the San Diego Padres, Tuesday, May 4, 2021, in San Diego. (AP PhotoGregory Bull)

The Padres scored in the seventh off reliever David Bednar to narrow the gap to 2-1. With one out, Nola singled to drive in Will Myers from second base. Bednar struck out Ha-Seong Kim and retired pinch-hitter Fernando Tatis Jr. on a popup to end the threat.

Kim, who replaced Tatis at shortstop, made two outstanding defensive plays in the second inning, including sprinting for a ball in shallow left field and throwing out Tom at third.

TRAINER’S ROOM

San Diego Padres shortstop Ha-Seong Kim, left, is greeted by teammate second baseman Jake Cronenworth during the second inning of a baseball game against the Pittsburgh PiratesTuesday, May 4, 2021, in San Diego. (AP PhotoGregory Bull)

San Diego Padres shortstop Ha-Seong Kim, left, is greeted by teammate second baseman Jake Cronenworth during the second inning of a baseball game against the Pittsburgh PiratesTuesday, May 4, 2021, in San Diego. (AP PhotoGregory Bull)

Pirates: Placed OF Gregory Polanco on the injured list without giving a reason. “I can’t comment on any of that. He’s on the IL. That’s all I can say,” manager Derek Shelton said.” To take Polanco's roster spot, the Pirates selected OF/INF Hunter Owen, whose first action will be his major league debut.

Padres: Lamet was reinstated from the 10-day IL and RHP Miguel Diaz was optioned to the alternate training site.

UP NEXT

Pittsburgh Pirates starting pitcher Mitch Keller works against a San Diego Padres batter during the first inning of a baseball game Tuesday, May 4, 2021, in San Diego. (AP PhotoGregory Bull)

Pittsburgh Pirates starting pitcher Mitch Keller works against a San Diego Padres batter during the first inning of a baseball game Tuesday, May 4, 2021, in San Diego. (AP PhotoGregory Bull)

Pirates RHP JT Brubaker (2-2, 2.63 ERA) pitches Wednesday against RHP Yu Darvish (3-1, 2.13) in the final game of the series.

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