SAN FRANCISCO - It was one thing seeing Travis Driskill come from nowhere this season to earn his first few major-league victories. It was another to see him yesterday, facing Barry Bonds in the fifth inning, as the new stopper of the Orioles' pitching staff.

Driskill later called that inning "one of the most taxing" he could remember, but he survived with the lead, and the bullpen held on for a 4-2 victory over the San Francisco Giants at Pacific Bell Park.

With the win, Driskill became the fourth rookie in Orioles history to start a season 5-0. The others are Ben McDonald (1989), Rocky Coppinger (1996) and Rodrigo Lopez, who accomplished the feat this season.

Even more impressive, all five of Driskill's victories have come on the road, and all have come after an Orioles loss. That makes him their losing-streak stopper, a term normally associated with the likes of Roger Clemens and Pedro Martinez.

"You look at Travis on the mound and he's not intimidating," said Orioles manager Mike Hargrove. "But he's not afraid to throw anything at any time in the count. He doesn't lose his composure. He doesn't panic."

The Orioles are 6-0 when Driskill starts, and he tried to deflect the credit after they broke their two-game losing skid and improved to 4-5 on this four-city road trip that concludes here today.

"Every time I pitch, something's coming up good," Driskill said. "Whether it's the defense or the offense coming up with something big, it's just a team effort every time."

Marty Cordova gave the Orioles the lead with a second-inning home run off Giants starter Ryan Jensen (6-6). It was Cordova's third homer in two games, and all of them have been bases-empty shots with two outs.

All of the Orioles runs, in fact, came with two outs. Melvin Mora extended his hitting streak to nine games with a two-out double in the third inning, and Brian Roberts followed with a run-scoring single to center. In the fourth, Mike Bordick hit a two-run triple that bounced past Giants right fielder Marvin Benard, stretching the lead to 4-0.

Protecting the lead wasn't easy for Driskill, who allowed the leadoff batter to reach base in four of his five innings. Shawon Dunston singled to start the fifth inning, and Pedro Feliz followed with a two-run homer.

"It looked like Travis really got tired there in the fifth inning," Hargrove said. "He started leaving his pitches up."

Driskill had thrown just 50 pitches going into the inning, but many of them were thrown with runners on base. After the Feliz homer, Driskill recorded two outs, and then Rich Aurilia reached on a bunt single, bringing Bonds back to the plate.

A crowd of 41,269, the 20th sellout of the season at Pac Bell, stirred. Bonds came to the plate with no one on base in his first two at-bats, grounding to first and popping harmlessly to third.

This time, Driskill was more careful, walking Bonds on six pitches. Next it was Jeff Kent, who is batting .368 in his past 28 games, and Driskill also walked him on six pitches.

That loaded the bases for Damon Minor, who swung at Driskill's first pitch and flied out to center, ending the inning.

"Physically I don't think I was tired, but mentally I was tired," said Driskill, who threw 78 pitches. "It was the toughest inning since I've been here."

So Hargrove turned to the bullpen. Willis Roberts pitched a scoreless sixth inning against the bottom of the Giants' order. Then Buddy Groom followed with two scoreless innings, and Jorge Julio pitched the ninth for his 14th save.

In Bonds' final at-bat, he came to the plate with a runner on first and one out in the seventh inning. Groom battled him to a full count, then threw strike three with a slider on the outside corner.

Groom is the only pitcher on the Orioles' staff who had ever faced Bonds before this series. Bonds is now 0-for-5 against him.

"I like the idea of being able to do that," Groom said. "But eventually it's got to even out."