CHICAGO -- Just about the only person not surprised about Carlos Silva's unblemished record is Carlos Silva.
After going 5-18 with a 6.81 ERA in two frightful seasons for the Seattle Mariners, Silva is 5-0 with the Cubs. His latest victory came Tuesday night, when he gave up Todd Helton's first homer of the season but otherwise pitched six splendid innings in Chicago's 6-2 victory over the Colorado Rockies.
"I didn't know too much about him," said teammate Ryan Theriot, whose two-run single capped a three-run eighth inning that broke open the game. "He's been a pleasant surprise, super-consistent each time out. I'd hate to think where we'd be without him."
Even with Silva, the Cubs are a disappointing 18-22, but they take a three-game winning streak into a road trip that starts Wednesday at Philadelphia.
Cubs manager Lou Piniella said he had no idea what to expect from Silva, who came to Chicago from Seattle in December's Milton Bradley trade. The Mariners wanted to get rid of the 31-year-old right-hander so badly that they paid the Cubs to take him.
"We found out rather quickly in spring training that he was healthy," Piniella said. "When a pitcher's healthy and he's had success like he did in Minnesota (47-45 from 2004-07), you figure you've got a chance. We're fortunate."
Asked if he was surprised to have joined the Yankees' Andy Pettitte and Phil Hughes and San Francisco's Tim Lincecum as the majors' only 5-0 pitchers, Silva smiled and said: "No. I was surprised the last two years, how bad I was."
He got nice support Tuesday from three Chicago rookies as the Cubs won a series for only the fourth time this year. Tyler Colvin had three hits, Starlin Castro drove in two runs and James Russell pitched an impressive inning of relief.
Silva took a five-hit shutout and a 3-0 lead into the seventh. Then he issued his only walk (to Troy Tulowitzki) and made his only mistake: a 3-2 fastball that Helton deposited into the right-field bleachers.
It was the first home run since Sept. 30 for Helton, once one of baseball's most feared power hitters.
"The most important thing is we didn't win, but it did feel good to actually hit a home run," he said. "It's been a long, long time."
Helton, who has nine RBIs this season, averaged 35 homers and 118 RBIs in his first seven full years with the Rockies but only 15 and 73 over the last five years.
"He is going to find his way. Other people need to join him," said Colorado manager Jim Tracy, whose team scored just four runs in the two losses to the Cubs. "You need a two-out hit once in a while. I'm not saying you're going to get one every time, but you need one every once in awhile."
Then came Chicago's three-run eighth off Rafael Betancourt. Colvin singled, Soto walked, Castro singled to make it 4-2 and Theriot had his two-run hit.
Rockies starter Jhoulys Chacin (2-2) allowed three runs on five hits and five walks in 5 2/3 innings. After pitching 14 1/3 scoreless innings in winning his first two starts, the 22-year-old rookie has given up nine runs over 10 2/3 innings in two losses.
Colvin, Castro and Kosuke Fukudome drove in Chicago's fourth-inning runs.
Silva also won his first five decisions in 2004. He became the first Cub to start 5-0 since Greg Maddux in 2006 and the first starter to begin his Chicago career with five wins since Mark Clark in 1997. ... Castro's RBIs were his first since he drove in six runs in his May 7 big-league debut. ... Olivo left the game in the seventh after landing face-first in the dirt while stealing second base. Tracy said Olivo complained of a sore neck. ... Rockies CF Carlos Gonzalez extended his hitting streak to 12 games.