DENVER (AP) Todd Helton started his final homestand with a key single in the eighth inning that helped the Colorado Rockies beat the St. Louis Cardinals 6-2 on Monday night.Charlie Blackmon had three hits and drove in three runs for the Rockies, who prevented the Cardinals from taking over sole possession of first place in the NL Central. They remained tied with the Pittsburgh Pirates, who lost 2-0 to San Diego.Matt Carpenter and Matt Adams had two hits each for the Cardinals.Helton was playing in front of Colorado fans for the first time since he announced his plans to retire at the end of the season, his 17th. He received a standing ovation when he came to the plate in the first, and Cardinals starter Lance Lynn stood behind the mound and waited as the crowd saluted Helton.The first baseman was given a loud ovation in each of his four plate appearances. His night started slow, but he had a big hit during the decisive rally.Troy Tulowitzki led off with a walk against reliever Trevor Rosenthal (2-4), and one out later Helton singled to center to put runners at the corners. Wilin Rosario singled to give Colorado a 3-2 lead.Helton was caught in a rundown between third and home for the second out, but Blackmon doubled to right to score Josh Rutledge from first to make it 4-2.Pinch-hitter Ryan Wheeler's two-run single off John Axford gave the Rockies a 6-2 cushion.Collin McHugh started for Colorado in place of lefty Jorge De La Rosa, who has a sore thumb on his pitching hand that forced him to miss his turn in the rotation. McHugh allowed one run on four hits, with the only damage coming on David Freese's RBI single in the fifth.He left after throwing 75 pitches in five innings.Lynn stuck around longer and got stronger as the game progressed. He scattered four hits through six innings and didn't let a runner past first after Tulowitzki's double before running into trouble in the seventh.After Lynn retired Helton in a nine-pitch at-bat, Rosario singled and moved to third on Rutledge's bloop single to right.Left-hander Kevin Siegrist relieved Lynn, and Blackmon lined an RBI single over the pulled-in infield to give the Rockies a 2-1 lead.The Cardinals tied it in the eighth on Carpenter's RBI double off Chad Bettis (1-3) that scored pinch-runner Pete Kozma from second.The Rockies took a 1-0 lead in the first on Tulowitzki's RBI double.NOTES: Rockies OF Carlos Gonzalez will see a hand specialist in Cleveland this week to see if he needs surgery on his injured right middle finger. "It looks like I'm going to," Gonzalez said. "I think that's what is best for my finger right now. I'm thinking about the future. I don't want to continue to deal with the same pain over and over. If that's what I have to do, I'm going to do it." ... The Rockies made a donation to the American Red Cross Disaster Relief Fund as the area recovers from devastating flooding. ... Cardinals OF Matt Holliday entered Monday hitting .358 against his former team.