Rafael Devers made some dubious history on Thursday.

Leading off the eighth inning, the Red Sox third baseman struck out on an automatic strike, making him the first Major League player to strike out on a rules violation

Under the new pitch clock rules, the batter has to be ready to be pitched to – or officially “attentive to the pitcher” – with eight seconds left on the pitch timer. Devers was looking down and kicking his cleats in the dirt when the clock showed ‘8’. Home plate umpire and crew chief Lance Barksdale made the call.

“There’s no excuse,” Boston Manager Alex Cora said. “They know the rules.”

The play happened with the Red Sox down 10-4, but they rallied for three runs after Devers’ technical knockout and left a runner in scoring position. An extra out might have been valuable as Boston attempted a comeback.

Devers was 2 for 3 with an RBI double before the strikeout. He also had less time to adjust to the new rules as he played for the Dominican Republic in the World Baseball Classic, an event that used old rules.

But hitters were not alone in trying to adjust to the new pitch clock on Opening Day. Chicago pitcher Marcus Stroman is trying to make it work.

“It’s tough, this pitch clock. It’s a big adjustment,” he said.

Stroman committed baseball’s first regular-season pitch-clock violation in the third inning of the Cubs’ 4-0 victory over Milwaukee on Thursday.

Stroman took a long look at rookie Brice Turang leading off second base with no outs and Christian Yelich batting at Wrigley Field. Just as Stroman turned his attention back to Yelich, plate umpire Ron Kulpa called the violation. Kulpa pointed to his wrist in announcing the call, and the automatic ball made it a 2-2 count against Yelich. Stroman didn’t argue.

“You got to be looking at the clock. You’re trying to worry about the pitch. You’re trying to worry about the guys on base. You’re trying to worry about your grip,” Stroman said. “There’s so many things going on now.

“So it definitely adds another layer to the game that’s tough, to be honest with you. It’s definitely not easy to be a pitcher out there and to feel rushed at times.”

Several more violations followed on the first day of regular-season games since MLB introduced a slate of rules changes this season – including a clock for a sport that famously existed for decades without any timers.

J.D. Davis of the San Francisco Giants became the first hitter called for a pitch-clock violation in any count during the ninth inning of a game at Yankee Stadium.

Meanwhile in Washington, Atlanta Braves reliever Collin McHugh put his arms out wide after being called for a violation by umpire Dan Bellino in the eighth inning against Washington.

That put batter Jeimer Candelario ahead 1-0, and McHugh followed with three more balls – a three-pitch walk, essentially.

“I didn’t even realize it happened, quite honestly,” Atlanta Manager Brian Snitker said. “It’s going to happen.”

New York Mets All-Star Jeff McNeil was angered by a violation called by plate umpire Larry Vanover in the sixth inning against Miami. McNeil was waiting for baserunner Pete Alonso to retreat to first after a foul ball when Vanover dinged him for an automatic strike. That prompted an argument with McNeil and Mets manager Buck Showalter, who seemed irritated that the pitch clock began before Alonso returned to first.

It worked out for McNeil — he grounded an RBI single a few pitches later.

THURSDAY’S OPENERS

BRAVES 7, NATIONALS 2:  The Atlanta Braves overcame the early exit of NL Cy Young Award runner-up Max Fried because of a strained left hamstring with four hits by Travis d’Arnaud and three errors by host Washingto

Fried allowed one run before departing with what Atlanta said was left hamstring discomfort after wincing as he he ran to cover first base for the initial out of the fourth inning.

Braves Manager Brian Snitker said last year’s runner-up in NL Cy Young Award voting definitely will miss at least one start and probably will end up on the 10-day injured list.

YANKEES 5, GIANTS 0: Aaron Judge followed his record-setting 2022 by homering on his first swing as Yankees captain, starting New York’s home win.

Gerrit Cole (1-0) struck out 11 in six scoreless innings, a Yankees record for an opener, and 21-year-old Anthony Volpe went 0 for 2 with a walk, stolen base and two nice defensive plays in his major league debut.

Gleyber Torres added a two-run homer in the fourth and Judge blooped an RBI broken-bat single in a two-run seventh that included DJ LeMahieu’s run-scoring single.

Logan Webb (0-1) struck out 12, the most for the Giants in an opener. Cole and Webb joined Dave McNally and Sam McDowell in 1970, and Max Scherzer and Jacob DeGrom in 2019 as the only opposing starters with double-digit strikeouts in an opener since 1901.

PHILLIES 11, RANGERS 7:  Jacob deGrom had a rough debut for the Texas Rangers.

The two-time National League Cy Young Award winner struck out the first batter he faced on three pitches and finished with seven strikeouts.

But while he was throwing plenty of strikes, he gave up five runs and six extra-base hits over 3 2/3 innings against the NL champion Philadelphia Phillies in the season opener, at Arlington, Texas.

DeGrom, who signed a $185 million, five-year contract as a free agent in December, still avoided a loss in his first start with his new team. Texas’ bats bailed him out after he exited, scoring nine times in the fourth against Aaron Nola and two Phillies relievers.

METS 5, MARLINS 3: Brandon Nimmo broke a seventh-inning tie with a two-run double, sending Max Scherzer and New York to a win at Miami.

Scherzer (1-0) coughed up a three-run lead but threw six solid innings in a matchup with NL Cy Young Award winner Sandy Alcantara as the Mets improved to 41-21 on Opening Day — the best record in baseball.

BLUE JAYS 10, CARDINALS 9: George Springer had five hits and Vladimir Guerrero Jr. drove in three runs as Toronto won at St. Louis despite the Cardinals’ Tyler O’Neill tying a major league record by homering on Opening Day for the fourth straight season.

Springer was 5 for 6 with five singles in the fourth five-hit game of his big league career to go along with a six-game game for Houston at Oakland in May 2018. Springer combined with Baltimore’s Adley Rutschman to become the first pair of players with five hits each on Opening Day since at least 1901.

WHITE SOX 3, ASTROS 2: Andrew Vaughn’s tie-breaking, two-run double in the ninth inning lifted Chicago to a win at Houston over the  defending World Series champion Astros.

The game was tied at 1 after a homer by Chicago’s Yasmani Grandal in the eighth. Ryan Pressly (0-1) walked Tim Anderson with one out in the ninth before a single by Luis Robert Jr.

Vaughn then belted a double on a line drive that sailed over the head of leaping second baseman Mauricio Dubón and into center field to put the White Sox on top.

Pedro Grifol got the win in his managerial debut after spending the last 10 seasons as a coach in the Royals’ organization. It snapped a streak of 10 straight wins for the Astros in openers.