Baltimore rookie pitcher Jake Arrieta was even better in his second start in leading the Orioles to a 4-1 win over San Francisco at AT&T Park on Tuesday.

The 24-year-old right-hander limited the Giants to three hits and one earned run with two walks and three strikeouts in helping the Orioles split the first two of the three-game series.

Arrieta beat the New York Yankees in his first start by allowing three earned in six innings and he appeared to more comfortable in his second outing. He was more economical with his pitches and the rookie did a better job of getting ahead of hitters.

The only run he gave up was on a 1-0 pitch to Pablo Sandoval, who hit his sixth home run to pull the Giants within 2-1 in the third.

But that was as close at it got as Arrieta allowed just one more hit the rest of his outing and the offense got to Joe Martinez (0-1), who was called-up from Triple-A Fresno to replace the injured Todd Wellemeyer.

David Hernandez pitched a harmless ninth for his second save.

Ty Wigginton drove in the first two runs with RBI groundouts and Adam Jones hit a solo shot in the fourth off Martinez for a 3-1 advantage.

Martinez went 6 1/3 innings while allowing eight hits, four earned and one walk with one strikeout.