The Red Sox posted their eighth win in 10 games after blowing two six-run leads in a loss on Friday night. The matchup was tied at 3 before slumping Bobby Dalbec's pinch-hit homer in the sixth inning.
Rafael Devers had four hits for Boston, and Kiké Hernández added a two-run single.
Robinson Chirinos belted a two-run shot for Baltimore. The Orioles have lost three of four.
Eovaldi (2-2) threw 108 pitches in his 211th major league start. The 32-year-old right-hander allowed two earned runs, struck out six and walked one.
It's the most starts prior to throwing a complete game in MLB history, according to STATS.
“It definitely means a lot to me," Eovaldi said. ”Especially with how the game's changing now and things like that, and injuries I've had."
Eovaldi had Tommy John surgery twice — once in high school and again in 2016 — and was sidelined in 2019 after having “loose bodies” removed in his elbow a year earlier.
“Every starter wants to go out there and finish his start,” he said. “It means a lot to me.”
There was some applause when he trotted out for the ninth with the rarity of complete games in baseball.
Boston's bullpen was tagged for 10 runs on Friday.
“He was great, especially in the second part of the game,” Red Sox manager Alex Cora said. “We needed to re-set (the bullpen) at one point."
Cora didn't know it was Eovaldi's first complete game until it was over.
“It was good to see them celebrate him down (in the clubhouse), well deserved," Cora said.
Less than 12 hours after wiping out a six-run deficit by outscoring the Red Sox 10-0 over the final three innings, the Orioles tied it at 3 in the fifth when Chirinos hit a hanging curveball from Eovaldi over the Green Monster.
The Red Sox had erased an early 1-0 hole when Jackie Bradley Jr. lined a run-scoring double and Hernández followed with his single that trickled into shallow left off the glove of diving third baseman Ramón Urías.
Orioles starter Jordan Lyles gave up three runs in 4 1/3 innings.
Orioles: A day after saying that 24-year-old INF prospect Jahmai Jones had season-ending Tommy John surgery, they designated him for assignment and called up RHP Cody Sedlock.
Red Sox: Placed RHP Hansel Robles on the 15-day injured list with back spasms.
In addition to Robles going on the IL, the Red Sox demoted right-hander Hirokazu Sawamura to Triple-A Worcester and recalled right-handers Ryan Brasier and Phillips Valdez.
Baltimore’s Rougned Odor went 0 for 4, ending his career-best 11-game hitting streak.
For the nightcap, Orioles right-hander Denyi Reyes (0-0, 0.00 ERA) is expected to make his first major league start and second appearance against Boston righty Josh Winckowski, who is slated to make his major league debut.