SAN FRANCISCO — Madison Bumgarner’s 24-inning postseason scoreless streak ended in startling fashion Monday night when Chicago Cubs pitcher Jake Arrieta hit a three-run homer off the San Francisco Giants ace.

Arrieta connected in the second inning during Game 3 of the NL Division Series to put the Cubs ahead as they tried to sweep the best-of-five matchup.

Arrieta sent a 1-2 pitch into the left-field bleachers at AT&T Park.

Bumgarner pitched a four-hit shutout in the NL wild-card game last Wednesday at the New York Mets. The 2014 World Series MVP had never given up a home run to a pitcher in his seven-plus major league seasons.

The left-hander had also thrown 24 straight scoreless innings with the Giants facing postseason elimination, a separate string that ended with Arrieta’s shot.

Arrieta called Bumgarner great but “beatable” leading up to the marquee pitching matchup. Arrieta is the reigning NL Cy Young Award winner. He hit .262 this season with two home runs while winning 18 games.