The Rockies couldn't hit Kris Medlen, who threw almost nothing but strikes.

The Braves didn't have to rely on hits against Colorado's Tyler Chatwood, who threw far too many balls.

Chatwood matched his career high with five walks and gave up six runs in only three innings as the Rockies lost to Medlen and the Braves, 6-1, on Monday.

Chatwood (4-4) gave up six runs, five earned, in only three innings. He gave up only three hits but couldn't overcome the walks.

"There was no consistency to his release point," said Rockies manager Jim Tracy, who said that Chatwood's 74 pitches in three innings "is really not a formula for success."

"He couldn't get his fastball in the strike zone," Tracy said.

By comparison, Medlen was masterful. He threw 111 pitches, including 85 strikes.

Medlen (7-1) struck out a career high 12 to win his sixth straight decision. He allowed five hits without a walk in his second complete game of the season.

"He was terrific," said Tracy of Medlen. "And he's been terrific for a while.

"He had three pitches for strikes whenever he wanted them. Unfortunately, with the way he's been throwing the ball, we pretty much put him in a rocking chair right from the outset."

Chatwood loaded the bases with three walks in the third. Martin Prado drove in Michael Bourn with a flyball to centerfield. Juan Francisco's single drove in Jose Constanza. Ross added a two-run double for a 6-0 lead.

"I just really didn't have good fastball command today," Chatwood said. "It's tough pitching behind in counts, especially against a team like that."

Two walks and a wild pitch by Chatwood and two errors on one play by first baseman Jordan Pacheco helped the Braves score two runs in the first.

After walks to Bourn and Freddie Freeman, Bourn scored from third on a wild pitch. Prado hit a sharp grounder off Chatwood's left leg. Pacheco couldn't handle Chatwood's throw to first base, and Pacheco then made a wild throw to third base for another error, allowing Freeman to score.

Prado was awarded a hit on the play in a scoring change after the game.

Medlen extended his streak of scoreless innings to 34 2-3 — the Braves' longest since Greg Maddux in 2000 — before the Rockies scored an unearned run in the seventh.

Medlen appeared in 38 games in relief before moving into the rotation on July 31. He is 6-0 with a 0.54 ERA in seven starts. He spent most of 2011 on the disabled list recovering from elbow ligament-replacement surgery on Aug. 18. 2010.

Medlen was 5-0 as a starter in 2010. The Braves have won his last 18 starts.

Medlen said adding a curveball as a starter has been "huge."

"You can just attack guys so differently with an extra pitch, an effective pitch, too," he said. "I got a couple strikeouts with it."

Medlen said he is glad he doesn't have to worry about an innings limit, but he noted pitching in relief "was not easy on your arm."

"You're not throwing as many innings, but you're getting up and warming up just as much as anybody," he said. "I love the starting part because you can get four days to prepare your arm."

David Ross hit a two-run double in Atlanta's four-run third inning.

A throwing error by shortstop Paul Janish helped the Rockies score an unearned run in the seventh inning, the first run allowed by Medlen since Aug. 11.

Carlos Gonzalez singled and scored from first when Janish dove for Pacheco's grounder and threw wild to second base for an error. Pacheco advanced to third on his single and Janish's error, but Medlen struck out Tyler Colvin and Chris Nelson to end the inning.

Medlen's streak of scoreless innings was the longest for a Braves pitcher since Maddux did not allow a run in 39 1-3 consecutive innings from Sept. 2-28, 2000.

Prado made his second straight start at second base. Gonzalez has benched All-Star Dan Uggla, who is hitting only .208.

NOTES: Pacheco has a 12-game hitting streak. ... Medlen's previous career high was nine strikeouts. ... RHP Randall Delgado, recalled from Triple-A Gwinnett, will pitch out of the Braves' bullpen. The Braves announced after the game RHPs Julio Teheran and Cory Gearrin will join the team on Tuesday. ... C Brian McCann, who had a cortisone shot in his right shoulder after Saturday's game, missed his second straight start. ... Rockies SS Troy Tulowitzki, on the 15-day DL with a groin injury, played as a DH on Monday with Triple-A Colorado Springs and is scheduled to play shortstop with Double-A Tulsa Wednesday and Thursday. ... Braves RHP Tommy Hanson will try for his 13th win against Colorado LHP Drew Pomeranz (1-8) on Tuesday night.