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Ian Kennedy and Daniel Hudson have formed a great 1-2 punch at the top of the Diamondbacks' rotation, one reason the club is closing in on its first National League West title since 2007.

After a dominating performance by the former in last night's opener of a three-game set with the Pittsburgh Pirates, Hudson seeks to get Arizona closer to its goal tonight.

Kennedy became the NL's first 20-game winner after hurling eight innings of one-hit ball in last night's 1-0 victory. He matched a career high in strikeouts with 12 and is the fourth player in club history to reach the 20- win mark in a season.

"We had a nice little ceremony in there (locker room) for Ian," Diamondbacks manager Kirk Gibson said. "He deserved the win."

The victory also lowered Arizona's magic number to clinch the division to four as the club pushed its edge over idle San Francisco to 5 1/2 games. The Diamondbacks will host the Giants this weekend and are trying to make that a meaningless series from their side of things.

Justin Upton hit a sixth-inning homer in Arizona's second straight win for all of the offense, while Paul Goldschmidt and Miguel Montero added hits. Upton's 31st homer of the season just cleared the wall in left.

"I thought it was going to hang up and I was going to catch it like normal," Pirates left fielder Alex Presley said. "I got back there in time and thought I was going to be able to make a play on it, but it didn't work out."

Jeff Karstens pitched well in defeat, giving up five hits. He also collected one of two hits for the Pirates, who have been outscored 29-4 over a four-game slide and have also dropped nine of 11.

Hudson will look to keep the Pirates' bats on ice after he had a four-game win streak end on Wednesday despite a quality start versus the Dodgers. The right- hander, coming off his third complete game of the season, allowed a pair of runs on five hits and three walks over seven innings of a 3-2 setback.

"They got two runs in the first off four infield singles, that's baseball," Hudson said. "I had better command overall and got locked in after that."

Hudson is 16-10 with a 3.39 earned run average this season and is a solid 9-4 with a 2.93 ERA in 15 games at home. The 24-year-old has posted a 1.35 ERA over two career starts versus the Pirates without a decision.

Though he pitched well, nine days of rest could not help Charlie Morton avoid a fourth straight loss last time out and the Pirates righty hopes to find the win column tonight for the first time since Aug. 8.

Morton gave up three runs and six hits over seven innings of a 3-2 loss to the Cardinals. Despite his longest outing in five appearances, he has just two victories since June 15 and fell to 9-10 with a 3.81 ERA this year.

The 27-year-old will be facing the Diamondbacks for the fourth time in his career and is 1-1 with a 7.20 ERA over the previous three encounters.

The Diamondbacks have won two straight over the Pirates following a five-game series losing streak.