DENVER -- There was a time when Jorge De La Rosa was a head case, the slightest mistake perturbing him to no end. These days, he rarely rattles.
"If he keeps that same mentality, there's no reason he can't be one of the best," said Clint Barmes, who hit a three-run homer in the eighth. "He's got unbelievable stuff."
De La Rosa (1-0) kept the Padres off-balance with a fastball that consistently reached 94 mph. But his changeup was even more effective as he struck out nine and enticed San Diego to roll into 10 groundball outs.
"Today was all about De La Rosa," Padres manager Bud Black said. "He threw the ball great. It's tough when you are throwing in the mid-90s, you have great arm speed with the changeup and you're hitting spots. It's difficult to hit when you have that kind of stuff."
And now he has the temperament to go along with that stuff.
This from a pitcher who failing to earn a win in his first 10 outings last year. De La Rosa then found his groove in June and went on to set career highs in victories (16) and strikeouts (193).
He had his emotions in check Friday. Then again, there wasn't all that much to throw him off rhythm.
San Diego had a potential rally in the fourth, when Kyle Blanks was hit by a pitch and Chase Headley followed with a single that trickled through the right side. But De La Rosa struck out Scott Hairston to end the threat.
"He has taken the next step," Jerry Hairston Jr. said. "You can tell."
Rockies manager Jim Tracy certainly can. This isn't the same pitcher he saw last season at this time.
"His poise and his persona on the mound is all different," Tracy said. "It's a sign of growth."
De La Rosa won in April for the first time since 2007 with the Kansas City Royals -- back when he easily was flustered.
"Right now, he's on top of it," said Miguel Olivo, who had two hits and drove in a run. "In K.C., he got a little frustrated when it didn't go the way he wanted it to. Then he came here and he became a different pitcher. I know he can pitch. I know he's got all the stuff. He's got his comfort back."
Colorado got off to a rough start in Milwaukee, losing two of three. The defense was suspect, bullpen shaky and offense sporadic.
That wasn't the case in the home opener. The Rockies were solid all afternoon in the field, received two scoreless innings from the bullpen and came up with timely hitting.
Colorado broke open the game with four runs in the eighth.
"The way we went out today says a lot to who we are," said Barmes, who hit his first homer of the year.
"Richard wasn't bad," Black said. "He matched him. ... We couldn't muster anything against [De La Rosa]. Even our hit was a ground ball that bounced through. He was on."
Padres first baseman Adrian Gonzalez was agitated after he wasn't awarded first base on a pitch he felt grazed him in the opening inning. Gonzalez argued for several minutes with home plate umpire Mike DiMuro, before stepping back in the box and striking out. "I'm not going to fake something," Gonzalez said.