San Francisco (8-11) dropped two of three at home to Arizona (13-5) last week, losing the final two games to Owings (3-0, 2.29 ERA) and Webb, who will start Tuesday's contest.

The Diamondbacks' next three starters - including Dan Haren - are all unbeaten, but Owings is probably the biggest surprise of that group. As a rookie last season, the right-hander went 8-8 with a 4.30 ERA in 29 appearances, including 27 starts.

He's won all three of his outings this season after yielding one run and six hits over six innings last Tuesday in an 8-2 win over the Giants. Owings, who made a slight tweak to his changeup before this season, improved to 2-1 with a 3.79 ERA in three career starts against San Francisco.

"I feel a lot better with it this year," said Owings about the changeup. "I've been able to use it more and more, lefties and righties. I have a lot of confidence in it."

Owings has 19 strikeouts to just five walks this season in 19 2-3 innings.

"He's throwing strikes and getting ahead," Diamondbacks manager Bob Melvin told his team's official Web site. "He's got a better changeup this year, a better slider."

Owings will be matched up against Kevin Correia (1-2, 4.12) for the second straight start. Correia gave up five runs and five hits in six innings Tuesday, and continued to have problems with Arizona leadoff hitter Chris Young.

Young went 1-for-2 with a two-run homer against Correia, improving to 3-for-8 in his career against the right-hander, with all three hits going for home runs.

"He's such a good mistake hitter. Every time I make a mistake to him, he hits it," Correia said. "There are a lot of guys I can get away with those mistakes. Not him."

Correia fell to 0-2 with a 3.95 ERA against Arizona in 11 appearances, including three starts.

The Giants went 1-5 on their first road trip of the season, but are playing better on their second one. They improved to 2-1 on this seven-game stretch away from home with an 8-2 win at St. Louis on Sunday.

Catcher Bengie Molina hit three doubles and drove in three runs as San Francisco finished with season highs in runs, hits (14) and margin of victory.

"We came out swinging," manager Bruce Bochy said. "We came in here playing a hot team and Bengie got the big hit to drive in a couple that seemed to get things contagious."

Molina went 1-for-10 in last week's series against the Diamondbacks.

Arizona had a four-game winning streak snapped with a 9-4 loss to San Diego on Sunday. First baseman Conor Jackson, however, capped his strong series by going 3-for-4.

Jackson went 8-for-14 and scored six runs over the weekend, and is batting .379 (11-for-29) with 12 runs scored and nine RBIs in nine games at home.