PHOENIX -- Getting on top of the ball has got Ian Kennedy on a roll.

Utilizing a tweak to his mechanics, Kennedy matched a career high with 12 strikeouts in six innings for his second straight solid start, helping the Arizona Diamondbacks rout the Colorado Rockies 10-0 Tuesday night.

He won't say what the adjustment was, only that it has helped him keep on top of the ball over his past two starts. Whatever it is, it sure seems to be working.

"It's a secret," Kennedy said after joining Randy Johnson as the only Arizona pitchers to strike out at least 12 in six innings or less. "It was just a minor mechanical thing. Sometimes when I'm out there, I can feel myself get under pitches and it just tells myself that little key."

Finally getting some run support certainly didn't hurt.

A night after being shut out by the Rockies, the Diamondbacks hit early and didn't really stop, roughing up Rockies starter Jeremy Guthrie (3-4) for seven runs on their way to a season-high 17 hits.

Jason Kubel hit a two-run homer and drove in five runs. Gerardo Parra had a solo homer among his four hits. Aaron Hill hit a two-run shot and finished a double short of the cycle.

By the time they were done, the Diamondbacks had their most lopsided shutout victory since beating San Francisco 11-0 on Aug. 27, 2009.

"It was an all-around great effort," Arizona manager Kirk Gibson said.

The Rockies had been on a roll, the 4-0 victory over Arizona on Monday night their seventh in eight games. That came to a screeching halt behind Guthrie's worst road start of the season and an inability to put the bat on the ball against Kennedy or anyone.

Colorado struck out 16 times overall after getting 12 hits the night before and Guthrie had no answers after giving up as many runs as his previous four road starts combined.

"If they kick me off the team today, it wouldn't surprise me," Guthrie said. "I haven't earned a spot here to pitch very well and I respect the game. I understand how it works. I have seen guys come up and do very well and earn it and I have seen guys who have done very well and lose it. If I don't make another start here, it wouldn't surprise me. I will come to work every day as long as I have a jersey and do the best I can."

Kennedy (5-5) seemed to have good command of everything, despite struggling in the bullpen before the game.

The right-hander won 21 games and was fourth in NL Cy Young voting last year, firmly establishing himself as Arizona's ace. He got off to a decent start this season before a miserable May, opening the month with five losses while allowing 20 earned runs in 30 innings.

Kennedy regained form in his last start, giving up a run in 7 2/3 innings in a win over San Francisco on May 30 to end the longest losing streak of his career.

The right-hander was good again against the Rockies, striking out seven in the first three innings, including Guthrie and Dexter Fowler with runners on second and third to end the second. Kennedy kept getting Colorado's hitters to swing and miss after that, striking out 12 for third time in his career while allowing five hits.

"The curveball wasn't really good in the bullpen," Kennedy said. "But for me, to have my arm feel good and to have a good rhythm, I'm pretty happy with it."

Guthrie had the opposite feeling.

The right-hander had felt at home on the road this season, allowing six earned runs in 24 1/3 innings in four starts away from Coors Field while going 1-2 with an 8.87 ERA in the thin air.

He wasn't so good in his first start in the desert.

Hill hit his sixth homer of the season in the second inning off him and Kubel, swinging away on a 3-0 pitch in the third, lifted his fifth to the pool deck in right for another two-run shot. Kubel added a two-run single in the fourth inning and Chris Young chased Guthrie with an infield single that drove in another run and put Arizona up 7-0.

Guthrie allowed seven runs on 11 hits in 3 1/3 innings.

"We are going to keep pitching him," Rockies manager Jim Tracy said. "He is a guy we need, simply put. We have kids in this rotation and the kids the two previous days stepped up and gave us tremendous performances. He has to realize that he has to step up. We need him in the fold."

Game notes
Gibson gave Justin Upton the night off and might not play him Wednesday to give the right fielder a mental break. Upton is hitting .243 with four hits in his last 24 at-bats, and Gibson said he is pressing as he tries to break out of the season-long slump. ... Rockies INF Jonathan Herrera, who has been on the DL since May 23 with a strained right hamstring, will begin his rehab assignment with Double-A Tulsa on Wednesday. ... Arizona LHP Wade Miley, the starter Wednesday against Colorado, leads all rookies with six wins and a 2.72 ERA. ... Rockies LHP Josh Outman will make his second start after starting the season with eight appearances out of the bullpen.