SAN FRANCISCO — Maybe this little elbow injury to Ervin Santana was just a ruse, a way for the Angels to find a temporary rotation spot for a triple-A right-hander whose name looks as if it could be carved right into the Blarney Stone.
Because if ever there was a pitcher who was meant to start against the San Francisco Giants on Irish Heritage Night in AT&T Park, where Tuesday's pregame festivities featured bagpipes, kilts and Irish dancers, it was Sean O'Sullivan.
Filling in for the injured Santana, O'Sullivan thrived in such Celtic conditions, limiting the Giants to one run and five hits in seven innings of an 8-1 interleague victory that extended the Angels' winning streak to five games.
Mixing a sharp-breaking curve with his 93-mph fastball early in the game and adding a floater of a 76-mph changeup in the later innings, the 21-year-old from El Cajon struck out five and walked one in a masterful major league debut.
About the only thing missing for the 6-foot-2, 230-pounder, who bears a facial resemblance to actor Jack Black, was the apostrophe between the O and the S in his name on the back of his jersey.
"I actually did notice that," O'Sullivan said of the Irish celebration. "My grandfather passed away two years ago and he was a full-blooded Irishman, so I really enjoyed the feeling that he was here with me."
O'Sullivan was sent back to Salt Lake after the game so the Angels could call up a fresh arm in reliever Rafael Rodriguez, but if Santana is not ready to return by next week, O'Sullivan will return to start against Colorado next Tuesday.
"I was not disappointed," he said. "I was thrilled to have the opportunity tonight, and hopefully this will present more opportunities in the future."
He didn't think the opportunity would come this soon. O'Sullivan, a third-round draft pick out of Grossmont College in 2005, started the season at double-A Arkansas but moved to triple A when injuries and the death of Nick Adenhart forced the Angels to dip deep into the Salt Lake rotation for pitchers.
"I definitely didn't see it happening this quick," O'Sullivan said, "but the opportunity presented itself, and I made the best of it. . . . It was everything I thought it would be, from the lights, to the fans to having my family in the stands. It was a thrill."
It helped that the offensive barrage continued for the Angels, who banged out 15 hits, four of them by slumping catcher Mike Napoli. They had four doubles and two homers and have scored 43 runs with 70 hits, including 15 homers, during their win streak.
They have also found the National League West to their liking. They are 7-1 against the Dodgers, Giants and San Diego Padres and have hit .353 with 17 homers, 23 doubles and three triples and averaged 7.5 runs in those games.
"We felt confident we had more slugging percentage than we showed," Manager Mike Scioscia said, "and it's coming to life."
O'Sullivan, the 12th different pitcher, and fourth rookie, to start for the Angels this season, had a 1-0 lead before he took the mound, as Maicer Izturis doubled and scored on Juan Rivera's two-out double off starter Jonathan Sanchez in the top of the first.
The Angels broke the game open with four runs in the third, Izturis reaching on first baseman Pablo Sandoval's double error, Bobby Abreu hitting an RBI single, Rivera hitting an infield single and Napoli, who was in a seven-for-49 slump, blasting a three-run home run, his ninth of the season, into the left-field seats.
O'Sullivan, who was 6-2 with a 6.02 earned-run average in 10 games at Salt Lake, hit a hit a hard grounder off third baseman Rich Aurilia's glove for a leadoff single in the fourth and scored on Izturis' two-run homer to left, which gave the Angels a 7-0 lead.
The Giants didn't advance a runner to second base against O'Sullivan until the sixth inning, and they didn't score until the seventh.
"He pitched a great ballgame," Scioscia said. "He may not light up the radar gun or do anything that makes you go 'wow,' but he has a good breaking ball, good late life on his fastball, and when he changes speeds, you see what he can do."