ARLINGTON -- Pitcher Carlos Silva is still perfect, and it's because of the offense.

Alfonso Soriano hit a two-run homer, No. 299 of his career, to help Silva improve to 6-0, his best start ever, as the Cubs beat the Rangers, 5-4, on Sunday for their first road series win in a month.

  • 134 wins
  • 118 wins

Silva is the first Cubs starter to open a season 6-0 since Ken Holtzman did so in 1967.

"It's because they've been scoring a lot of runs," Silva said. "The whole rotation has been really good, but I've been getting more run support than anybody else."

The Cubs starters have posted 29 quality starts this season, but the pitchers are 11-9 in those games with nine no-decisions. They just haven't gotten runs like Silva.

"He was really efficient," Rangers starter C.J. Wilson said of Silva. "Their whole starting staff against us threw really well. [Ted] Lilly threw well, and that [Randy] Wells guy threw well and Silva threw well. And they all went pretty deep into the game. They obviously beat us innings-wise as starters. That's what I'm really upset about."

Silva is the 11th pitcher to begin his Cubs career at 6-0, and fifth to do so as a starter. That list includes Dizzy Dean (6-0 in 1938), King Cole (8-0 in 1910), Jack Taylor (7-0 in 1899) and Fred Goldsmith (7-0 in 1880).

The Cubs pulled Silva after 81 pitches because of the heat and humidity at Rangers Ballpark in Arlington. He gave up three runs on six hits and one walk over 5 1/3 innings. The right-hander is one of four pitchers without a loss in at least eight starts this season, joining Cincinnati's Mike Leake, San Francisco's Tim Lincecum and Tampa Bay's Jeff Niemann.

The key was a 4-0 lead in the first. Ryan Theriot singled to lead off against Wilson (3-2) and moved up on Starlin Castro's bunt single. Derrek Lee then singled, driving in Theriot, and Lee and Castro advanced an extra base on left fielder Josh Hamilton's errant throw. Marlon Byrd grounded out, driving in Castro. Soriano then hit his ninth homer off an 0-2 pitch from Wilson to open a 4-0 lead.

"That changed the whole game," Silva said of the Cubs' cushion. "I gave up a two-run homer [to Michael Young], but that lead made me comfortable on the mound. Getting a 4-0 lead changed my whole game and made me more comfortable."

Young's blast in the third made it 4-2, and Julio Borbon hit a two-out RBI single in the Texas fourth to close it to 4-3.

But the Cubs tacked on a run as Xavier Nady singled in the sixth, moved up two batters later, and was safe at home on a headfirst slide, scoring on Koyie Hill's single.

"He did what we needed to do," Cubs manager Lou Piniella said of Nady's risky slide. "Because of that, we won the ballgame. That was a big two-out hit by Koyie Hill."

"It was not an ideal slide," said Nady, who had a headache after the game. "I think I saw at the last second I could get my hand in there."

The Rangers made it interesting in the eighth. Borbon singled off John Grabow with one out and scored one batter later on Young's double off Bob Howry, making his 2010 Cubs debut after he was released by the D-backs on Monday. Sean Marshall went 1 1/3 innings and held an opponent scoreless for the 20th time in 24 appearances, and Carlos Marmol pitched the ninth for his ninth save.

Marshall struck out two of the five batters he faced. What's he doing?

"A lot of curveballs -- that's been the key to my season is I throw my curveball for strikes in different counts and I'm getting back in counts with it or putting guys away with it," Marshall said. "It makes my other pitches better."

One other player who has been better this season is Soriano, who made a diving catch of Vladimir Guerrero's fly ball for the second out in the third. It wasn't artistic, but he got the job done. Soriano is well aware he's approaching the 300-homer milestone.

"I'm trying not to think about it," said the left fielder, who was 6-for-16 on this road trip, with two homers and four RBIs. "I think about it before I get the at-bat, because I don't want to go to home plate thinking I'll hit one more. I think about it before and after. When you think about homers, it never happens."

The Cubs are taking this one day at a time as they try to climb back to .500. With the win, they clinched their first road series since sweeping the Brewers in Milwaukee, April 23-25.

Silva came into the game with a career 4-4 record and 5.20 ERA against the Rangers, and he had not faced them since September 2008.

"It's a whole different game," he said of pitching in the American League. "You have nine different batters. There's no holes in the lineup. I had a really good offense, really good defense and all I tried to do was throw strikes and make things happen."