When it was over, the Marlins prevailed 4-0, and Eovaldi looked more like a two-time Cy Young Award winner than Halladay.
The Marlins right-hander surrendered three hits and two walks in 7 2/3 innings to improve to 4-6 with a 3.50 ERA. He missed the season's first 2 1/2 months with a shoulder injury.
Eovaldi's impressive performance started with a 1-2-3 first inning.
"With a great first inning, as opposed to the 20- or 30-pitch first inning, the games usually go by a lot better," said Eovaldi, who struck out five. "I don't know what that is, but I usually have the hardest time at the beginning of the game."
This time, it was Doc Halladay who was hurtin' in the first -- literally. He lasted only three batters and 16 pitches due to what the team described as right-arm fatigue.
The Marlins scored a run with no hits and four walks in the first, and that run held up until Miami put together a three-run eighth.
Lack of run support is no stranger to Marlins starters, especially Eovaldi. He entered the game backed by 3.3 runs per nine innings. That was eighth lowest in the majors this season.
Since entering the bigs with the Los Angeles Dodgers in 2011, Eovaldi had received 2.96 runs -- lowest of any pitcher with at least 44 starts.
"Like I tell these guys,'"Control what you can control. You go have to go out there and pitch,' " Marlins manager Mike Redmond said. "You can't worry about how any runs you're going to get tonight. You have to go out there and put up zeroes, and that's something he's capable of doing."
In 17 starts this season, Eovaldi, 23, has produced 13 quality starts (pitching at least six innings and allowing three or fewer runs).
"I'm definitely pleased with the year I've had this year," he said, "but there's always a lot more room for improvement."
While that's certainly the case, Eovaldi already has some quality attributes to hone.
"I love his stuff," Redmond said. "The season got off to a little but of a late start for him being hurt, but he's come and done a nice job. I think he's proven what he's capable of doing in the big leagues. Now it's about consistency and being able to do it every five days.
"He knows that he can pitch up here. He knows what he has to do to be able to neutralize a lineup with his secondary pitches. Those will continue to be a work in progress. But he has 95-, 96-mph fastball and when his breaking stuff is on, like it was tonight, he's pretty good."
The biggest late-season adjustment for Eovaldi has been relying more on his curveball.
"These last two, three games I've been able to use the curveball more, and that's just a huge pitch for me because it changes the eye level," he said. "It's a slower pitch. My change-up's hard, I don't throw it as much. It takes them off the sight of the fastball."
Eovaldi is scheduled to make his final 2013 start against the Detroit Tigers on Saturday.
"It is nice, as we talk about the development aspect of where we're at, to see him put a night like tonight together," Redmond said. "It was fun to watch."