Bobby Dalbec, right, celebrates with Kevin Plawecki after hitting a tiebreaking home run in the sixth inning Saturday afternoon, lifting the Red Sox to a 5-3 win over the Orioles in the first game of a day-night doubleheader at Fenway Park. Michael Dwyer/Associated Press

BOSTON — Rougned Odor hit a three-run homer and the Baltimore Orioles beat the Boston Red Sox 4-2 Saturday to earn a split of a day-night doubleheader.

In the opener, Nathan Eovaldi pitched a seven-hitter for his first career complete game in Boston’s 5-3 victory.

Austin Hays and Ryan McKenna each had two hits in the nightcap for Baltimore, which has won two of the first three in a five-game series.

Christian Vázquez had three hits for Boston.

Odor homered just over Boston’s bullpen to make it 4-0 in the third inning. The drive came after Ramón Urías hit an RBI single against 23-year-old righty Josh Winckowski (0-1), who made his major league debut.

Winckowski lasted three innings, giving up four runs and six hits.

Making his first big league start, 25-year-old righty Denyi Reyes held the Red Sox to one run over 3 2/3 innings.

Joey Krehbiel (2-3) pitched 1 1/3 innings in relief for the victory. Jorge López got four outs for his sixth save.

In the opener, Rafael Devers had four hits for Boston and Kiké Hernández added a two-run single. Devers went 0 for 4 in the second game.

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 Eovaldi trotted out for the ninth. He gave Boston’s beleaguered bullpen a break after the Red Sox gave up 10 runs in the final three innings 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 (some) point.”

The opener was tied at 3 before slumping Bobby Dalbec’s pinch-hit homer in the sixth.

Dalbec, who entered hitting just .162, having lost most of his playing time at first base to Franchy Cordero, drove a fastball into Boston’s bullpen against Keegan Akin (1-1).

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.

TRAINER’S ROOM

Orioles: A day after saying that 24-year-old infield prospect Jahmai Jones had season-ending Tommy John surgery, they designated him for assignment and called up right-hander Cody Sedlock.

Red Sox: Placed right-hander Hansel Robles on the 15-day injured list because of back spasms.

BULLPEN SHUFFLE

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.

START ANOTHER

Baltimore’s Rougned Odor went 0 for 4, ending his career-best 11-game hitting streak.