Updated

The Giants' Tim Lincecum has already won two National League Cy Young Awards in his career. If Ian Kennedy keeps up his current pace, the Diamondbacks hurler may join him on that list of winners.

The two aces go head-to-head tonight when division-leading Arizona continues its big three-game series with San Francisco at AT&T Park.

Kennedy didn't find himself on too many preseason prediction lists for the NL's top pitching honor, but he has let his numbers do his talking for him this year. The right-hander came into the season with just 10 career victories, with all but one of them coming in 32 starts last year, but he became the first 17-game winner in the league when he bested the Padres on Sunday.

Kennedy improved to 9-1 in his past 10 starts after holding San Diego to one run on six hits over seven innings without a walk. He improved to 17-4 on the year with a 3.03 earned run average and hasn't given up more than three runs in any of his past 10 outings.

"I had the confidence that I could [win consistently]," Kennedy told Arizona's website. "It's a little harder at the big league level, but really, all you do is just try to be that consistent every time."

The 26-year-old beat the Giants on Aug. 1, giving up two runs over eight innings. He is 2-2 with a 1.87 ERA in eight career meetings with the Giants.

Lincecum, meanwhile, didn't look much like a Cy Young Award winner in his last outing on Monday, serving up a career-high three homers in a 7-0 loss to the Cubs. The right-hander hadn't allowed more than three runs in 13 straight starts before giving up four earned over six-plus innings.

The Giants have been shut out in Lincecum's past two losses and the 27-year- old is 12-11 with a 2.58 ERA on the season. He is 7-3 with a 2.43 ERA in his career when facing the Diamondbacks.

Lincecum will be looking to send the Diamondbacks to another loss this evening after the Giants took last night's opener, 6-2, to end Arizona's nine-game winning streak. Carlos Beltran had his best game since being acquired from the Mets in July, going 4-for-4 with a triple, two-run homer and three RBI in all. He had totaled just one homer and 20 hits over his first 20 games with the Giants while also spending time on the disabled list.

Cody Ross also hit a two-run homer to help San Francisco pull within five games of Arizona for first place in the NL West.

"It was nice to have a game like this," Giants manager Bruce Bochy said. "We had some big hits, long ball, two-out hits. We've been missing that for quiet awhile."

Matt Cain limited Arizona to two runs on five hits and four walks over eight innings as the Giants beat the Diamondbacks for the ninth time in 13 meetings this year.

Diamondbacks starter Joe Saunders (9-12) allowed four runs in 5 1/3 innings to take the loss, his club's first since Aug. 22.

Though Arizona failed to pad its lead in the NL West, manager Kirk Gibson isn't worrying after last night's defeat.

"They outplayed us tonight. If you want to second-guess plays that's fine, we didn't play good enough to beat them," he said. "We didn't pitch good enough to beat them. We had our opportunities and weren't able to execute it.

"We've been pretty [darn] good, we won nine in a row, so it's one game. No problem."

Miguel Montero doubled in a run for the D-Backs in the first inning before the Giants took control with a three-run third.