PHOENIX (AP) - Tim Lincecum shut down the Arizona Diamondbacks for the second time in less than a week. This time, he got enough support to finally earn his first win of the season.

The reigning NL Cy Young Award winner struck out 12 in eight innings and the San Francisco Giants beat the Diamondbacks 5-1 on Friday night for their fourth straight win.

''I just try to be as aggressive as I can with most teams,'' Lincecum said, ''and I really get more aggressive with these guys for some reason.''

Lincecum (1-1) got a no-decision last Saturday in San Francisco, striking out 13 over eight shutout innings in a 2-0 loss to Arizona. That's one run, 25 strikeouts and one walk in 16 consecutive innings against the Diamondbacks.

''I don't think it matters if you've just seen him,'' Giants manager Bruce Bochy said. ''With all good pitchers, if they're on, you've got your work cut out.''

Lincecum's performance marked the sixth consecutive outstanding performance by San Francisco's starters. In that span, they've allowed three earned runs in 42 2-3 innings.

''No one wants to be that guy who's struggling,'' Lincecum said. ''Everybody wants to keep this streak alive. Everybody wants to keep the roll that we've got going. The pitchers have been pitching really well. I think everyone's just kind of feeding off of it and we're just kind of going off that momentum.''

Bengie Molina went 3-for-5 with a home run and three RBIs in San Francisco's first road victory of the season in seven tries. Edgar Renteria also homered.

Doug Davis (1-3), the winner in last Saturday's duel, gave up five runs and nine hits in six-plus innings.

''He's got the stuff,'' Davis said of Lincecum. ''He's got above-average everything. He outpitched me, bottom line. ... I know I have to go out there and put zeros up when I face a guy like Tim.''

The Diamondbacks, coming off their first series win of the year, have not won consecutive games this season. The worst-hitting team in the majors (.224), Arizona only managed an RBI single from Davis.

Renteria connected in the first and Molina went deep leading off the third to give San Francisco a 2-0 lead.

Davis' two-out RBI single, after Justin Upton 's double, cut it to 2-1 in the fifth. But consecutive two-out singles by Aaron Rowand , Pablo Sandoval and Rich Aurilia restored the Giants' two-run lead in the sixth.

San Francisco scored twice more in the fifth when Molina's bases-loaded drive to deep right-center bounced off the tip of Chris Young 's glove for a two-run double.

The Diamondbacks had runners at second and third with one out in the first but Lincecum fanned Mark Reynolds - ''the key at bat of the game,'' Arizona manager Bob Melvin said - and Chad Tracy grounded out to second to end the threat.

Eric Byrnes doubled off the top of the left-field wall with two outs in the third. Melvin argued it was a home run, so umpires reviewed the play. The double call was upheld, and moments later the inning ended when Byrnes easily was thrown out trying to steal third.

''I thought it hit that pad and hit that pole behind it and came back,'' Melvin said. ''We've seen that in batting practice some. I wasn't 100 percent sure, but you've got to do the best you can to potentially get that. That's what the replay is for.''

Notes: Arizona LF Conor Jackson was scratched due to illness. ... Giants LHP Randy Johnson makes his first appearance in Arizona with a visiting team on Saturday. ''He should get a tremendous reception, for all he's done for that organization,'' Bochy said. ''They've got a World Series ring, and that doesn't happen without Randy Johnson .'' ... Arizona began a stretch of 40 games in 41 days.