It wasn't perfect for Romero who struck out four, but also walked four under windy conditions, but he said the key was that he was able to pitch out of jams.
Romero was 13-9 with a 4.30 ERA last year for the Blue Jays, pitching behind former Toronto ace Roy Halladay, who was dealt to the Philadelphia Phillies during the offseason.
Romero is the only returning Blue Jays starter who had double-digit wins last season.
Blue Jays manager Cito Gaston isn't penciling in Romero for opening day yet, but Romero has given up only one earned run in three starts this spring and didn't walk his first batter until Saturday.
Romero suffered a strained oblique just three weeks into the 2009 season, but recovered quickly after making the team out of spring training.
"He's absolutely got a chance to be the ace," Gaston said. "He could have been Rookie of the Year last season if he didn't get injured. He's at the top of the list."
Romero said he is a completely different pitcher than the one that made his debut last spring.
He struggled with his control and the wind against the Braves, but he maintained his composure, something he said he had big problems with last season. He got out of a first-and-third situation in the second inning and walked Braves pitcher Tim Hudson to lead off the third. Romero got a double play to end the inning.
In the fourth, he walked the first two batters. Once again, Romero settled down and got another double play grounder to get out of the jam.
Romero was more proud of how he handled adversity than the four shutout innings.
"Last year I would have folded right away," Romero said. That was only 12 months ago but it seems like a lot longer. Last year I would have tried to go with something other than what I had that was working. This time I went with what I had."
As far as the weather and the fact that there always seemed to be Braves on base, Romero said he was able to cope instead of letting it get to him.
"You have to pitch your game whether it's windy or there's runners on base," he said. "I'll keep working at it, but I have a different feeling this year."
Gaston has noticed.
"He got the outs when he needed to. It used to bother him, but he's got his confidence and he just keeps getting better."
Braves manager Bobby Cox said that batters were coming back to the dugout saying that Romero was practically unhittable.
"That guy was devastating," Cox said. "That's one of the best sliders I have seen. Nobody could hit it. If he can learn to get that pitch over, he's unhittable."
Hudson struggled in his four innings for the Braves, allowing seven hits and three runs, but he struck out six and said he is right on pace.
"I felt like I had my good stuff," Hudson said. "I wasn't great, but it was one of those days when you realize there are adjustments that need to be made. I feel good that I was able to go four innings."
Hudson missed almost all of 2009 after undergoing Tommy John surgery.
Dana Eveland took over for Romero and pitched three shutout innings with four strikeouts. Sean Henn and Rey Gonzalez each pitched a scoreless innings as the Blue Jays allowed only five hits.
The Blue Jays scored all three runs off Hudson. Travis Snider opened the Blue Jays second with a double and scored on Brad Emaus' single. The Blue Jays scored two more in the third.
Mike McCoy, Jeremy Reed, and Emaus each had two hits for the Blue Jays. Melky Cabrera had two singles for the Braves.