DENVER — Randy Johnson brought heat for two decades, and on some nights, he still can.

But it's a sputtering flame. And on a windy night at Coors Field, Johnson and the Giants were blown out. Matt Murton and Yorvit Torrealba hit back-to-back home runs in the fifth inning and the Colorado Rockies pounded Johnson in the sixth while rollicking to an 11-1 victory Wednesday.

The Big Unit allowed seven runs in 5·innings and failed to strike out a batter — just the seventh time that has happened in his 592 career starts.

"I'm not too worried about strikeouts," said Johnson, who ranks second to Nolan Ryan on the all-time list with 4,819. "Is it a sign? No, by no means. I'll try not to strike anybody out my next start but hopefully we'll win the game."

Johnson (2-3) remained at 297 career victories and is winless with a 11.37 ERA in three road starts. He has been a different pitcher at home. Just last Friday at AT&T Park, he punched out nine Rockies while holding them to four hits in seven shutout innings.

But even after that dominant start, his comments foreshadowed what might happen five days later.

"At age 45, I may not have those games back-to-back-to-back, like you see Tim (Lincecum) doing now that he's warming up," Johnson said Friday.

This time, the difference was a slider that lacked its usual sharpness. The altitude might have had something to do with that.

"The ball was over the middle of the plate," Johnson said. "My slider wasn't nearly as sharp as it was my past start. That was the biggest reason and I got hurt because of it."

The last time the Big Unit failed to record a strikeout in a start was Aug. 4, 2006, for the New York Yankees at Baltimore. Among his seven starts without a strikeout, he was knocked out before pitching four innings in all but three of them.

The road to Johnson's 300th victory could be long and winding. His next start would fall Monday against the Washington Nationals at AT&T Park, where he hasn't allowed a run in his past two outings. Johnson is lined up to pitch again on the homestand May 16 against the New York Mets.

He would need to win both games to have a shot at setting the 300 mark in Seattle, where he turned the corner from wild flamethrower to Cy Young Award winner. If the Giants don't tinker with the rotation, Johnson would start May 22 against the Mariners at Safeco Field.

Giants Manager Bruce Bochy didn't care to dwell on Johnson's start. He was dismayed at another weak offensive effort on what appeared to be ripe hitting conditions at Coors Field. It was a relatively warm night and the breeze could have coaxed a cannonball over the right-field fence. But a lineup of regulars couldn't touch Rockies right-hander Ubaldo Jimenez.

"That's what it came down to," said Bochy, who discussed lineup changes with the staff after the game. "Their guy pitched well and we didn't have a lot of opportunities today."

The Giants simply aren't getting enough baserunners. So when a clutch situation presents itself, they have little margin for error.

Their performance has been marginal, all right. They were 0 for 5 with runners in scoring position and avoided the shutout when Emmanuel Burriss scored on Juan Uribe's groundout in the eighth inning.

The Giants are hitting .209 with runners in scoring position. Only the Arizona Diamondbacks have been worse.

The Rockies didn't have the same trouble, even though they were coming off an extra-inning night game at San Diego and didn't arrive in Denver until 3 a.m. Wednesday.

"You can't say everybody needs to be more patient or more aggressive and that'll be the key to our success," said Randy Winn, who is hitting .228. "I don't think there's one thing that will get us rolling as an offense. We'll have to get some hits and hope the confidence follows after that."