(Sports Network) - Arizona ace Brandon Webb aims for his major league-leading and personal-best 19th win of the season tonight, when the NL West-leading Diamondbacks close out a three-game series versus the San Diego Padres at Chase Field.

Webb has won five straight starts and is unbeaten over his previous 10 trips to the hill (7-0). He last pitched on August 15 against the Houston Astros at Minute Maid Park, hurling eight innings of two-run ball in a 12-2 blowout. Webb, who has lasted at least six innings in 11 straight appearances, is 18-4 with a 2.85 earned run average in 26 starts this season.

The right-hander posted a career-high 18 wins a year ago and is 8-1 in 11 home starts this season. Webb will face San Diego for the second time this season after recording a victory on April 27 at Petco Park. He was reached for an unearned run in six frames of a 2-1 triumph, improving to 5-7 in 20 career starts in this series.

Arizona hopes Webb has his best stuff as it attempts for a three-game sweep of the Padres on Thursday. The D'Backs have won two straight, five of six and seven of their last nine games, including Wednesday's 8-6 victory in the second test of this set. Adam Dunn hit a three-run homer to highlight the offense for Arizona, which is two games ahead of the Los Angeles Dodgers in the division standings.

Conor Jackson and Mark Reynolds each finished with a hit and two runs batted in for the Diamondbacks, who got a solid showing from starting pitcher Dan Haren. Haren earned the win after allowing five runs on 11 hits in six innings of work.

Jody Gerut went 3-for-5 with a solo homer, and Kevin Kouzmanoff hit a two-run blast for the Padres, who have lost three in a row. San Diego ace Jake Peavy suffered the loss after surrendering six runs -- five earned -- on five hits and four walks in five innings.

Chad Reineke will make his second major league appearance on Thursday for the Padres. Reineke debuted on Saturday in an 8-3 win over Philadelphia, as he gave up three runs and five hits in five innings for the win.

Arizona leads the 2008 season series with San Diego by a 9-5 count.