SAN DIEGO -- Maybe the Colorado Rockies are finally getting the hang of playing on the road.
Behind Todd Helton's grand slam, the Rockies won their fourth straight game -- all on the road -- with a 4-2 victory over the San Diego Padres on Saturday night.
By taking the first two games against San Diego in the three-game series, Colorado set a franchise record by winning its fourth consecutive road series. After dropping the first game of a nine-game road trip, the Rockies have won four straight.
"It's satisfying," Helton said. "The biggest thing we have to do as a team and as an organization is to develop a winning attitude. We're getting closer."
The Rockies, who have never had a winning road record in 13 seasons, have had only four overall winning seasons in their history and none since 2000.
"Hopefully, we can keep this going this year and carry it over to spring training," Helton said.
Helton, one of the veteran leaders on an inexperienced team, hit a slicing home run down the left-field line off Brian Lawrence that proved to be the difference.
"For us to win four consecutive road series, especially with this group, speaks a little bit about the effort being put forth and the results," Rockies manager Clint Hurdle said.
The Rockies, with the NL's worst road record at 18-43, have won six of seven overall.
San Diego's lead in the NL West was cut to 5½ games over Arizona and the Los Angeles Dodgers. The Padres dropped to 63-65, making it the latest date that a division leader has had a losing record.
Helton's home run was about the only offense Colorado managed against Lawrence (7-13) and two relievers.
"That's a big hit in this ballpark," Hurdle said. "He's capable of a lot of things and he's finding his own way to contribute. We have one big hit tonight. He had it and it's a four-run swing. He picked us up big time with the bat."
Sun-woo Kim (3-2), making his second start for the Rockies since being claimed off waivers on Aug. 5, held the Padres to one run and four hits in five innings. The right-hander struck out seven and walked one. Kim, who threw 71 pitches, was on a pitch count of 70 pitches.
David Cortes pitched the ninth for his second save in two chances.
"The first two innings, my slider wasn't working," Kim said. "I decided to go with my cut fastball and change up more and it was better."
Lawrence cruised into the fifth, having allowed just two singles. But he ran into trouble after consecutive singles by Omar Quintanilla and Danny Ardoin to open the fifth.
Kim followed with a sacrifice bunt before Cory Sullivan was hit by a pitch to load the bases. After working the count to 3-1, Helton reached outside and went the opposite way for his 14th homer.
"It was a fastball because I wasn't going to walk in a run there," Lawrence said. "I was going to throw him a strike and make him hit the ball. I thought it was a good pitch. I would have never guessed the ball was going to go out of the park."
Helton's home run, his third career grand slam, sliced down the left-field line and just made it into the second deck of the Western Metal Supply Company building that borders the left-field foul pole.
"Just like any park, if you hit it hard enough, it's going to go out," Helton said. "I knew that I hit it good and that it wasn't slicing too much."
Helton is hitting .381 (8-for-21) with three home runs, three doubles and eight RBI in five games at Petco Park this season.
Lawrence gave up five hits in seven innings. He struck out three and walked none while allowing more than one run for the first time in three starts.
San Diego threatened in the eighth inning when Joe Randa hit a one-out single and Brian Giles followed with a double down the left-field line. Scott Dohmann replaced Jose Acevedo and gave up an RBI single to Ryan Klesko to cut the lead to 4-2.
Dohmann got Mark Loretta to pop out and ended the threat when he struck out Xavier Nady.
"We've been very cyclical with our hitting," Padres manager Bruce Bochy said. "That's what has kept us from getting on a roll and a nice winning streak."
Miguel Olivo put the Padres ahead in the second inning when he hit a two-out single to drive in Nady, who doubled and went to third on Kim's throwing error.
In 15 career games at Petco Park, Helton is hitting. 339 (19-for-56) with five home runs, four doubles and 13 RBI. ... The Padres have scored two or fewer runs in 13 of Lawrence's 27 starts. ... San Diego committed an error in its fourth straight game, totaling nine during the stretch. ... The Padres honored longtime broadcaster Jerry Coleman before the game for his recent induction into the Baseball Hall of Fame.