MLB: Los Angles Angels 8, San Francisco 1

The Angels’ Mike Napoli hit a three-run homer to help Sean O’Sullivan win his first major league start — an 8-1 Los Angeles victory over San Francisco.

O’Sullivan (1-0), who had the good fortune to make his debut on Irish Heritage Night at AT&T Park, gave up a run on five hits and struck out five over seven innings.

The 21-year-old San Diego native arrived from Class AAA Salt Lake City to become the 12th different starter this season for Los Angeles.

O’Sullivan had plenty of help on offense as the Angels outhit the Giants 15-5, including a four-run third inning keyed by Napoli’s blast. He then scored a run in the fourth on Maicer Izturis’ home run after reaching base on his first major league hit.

Jonathan Sanchez (2-7) took the loss after giving up seven runs — six earned — on 10 hits over 3 2/3 innings. A sacrifice fly from Nate Schierholtz in the seventh inning accounted for San Francisco’s lone run, making it 7-1.

Bobby Abreu singled in Vladimir Guerrero in the eighth to close out the scoring.