LONDON — Ian Happ was well aware of the new dimensions of the field at London Stadium.
After a slugfest between the Yankees and Red Sox in the inaugural London Series in 2019, the field for the Cubs-Cardinals showdown featured a wall that was seven feet deeper in center field and five feet deeper in the alleys.
Happ pointed to the difference in the baseballs four years ago as another reason he didn’t expect the fireworks show from the last installment of the event, which featured 50 runs over two games.
‘‘I don’t think it’s going to be a home-run derby out there,’’ he said before the Cubs’ 9-1 victory Saturday in the first of the two games.
Then he did his best to prove himself wrong.
Happ’s first homer served as an early turning point. Cubs left-hander Justin Steele and Cardinals right-hander Adam Wainwright had retired the side in order in the first inning. Happ, batting cleanup, led off the second.
He worked a 2-2 count, aided by a pitch-clock violation, then jumped all over a sinker that drifted over the middle of the plate. His towering blast cleared the tall center-field wall to give the Cubs a 1-0 lead.
‘‘ ‘Happer’ getting it started with the homer kind of let everybody relax a little bit,’’ manager David Ross said.
The Cubs tacked on another run in the second on consecutive singles from the bottom-of-the-order trio of Christopher Morel, Yan Gomes and Nick Madrigal.
Steele, meanwhile, mowed down the Cardinals, holding them hitless through the fourth and scoreless through the fifth.
‘‘Truly special,’’ Steele said of pitching in the big-event atmosphere, with a crowd of 54,662. ‘‘Felt like everybody was on the mound there with me.’’
Wainwright, on the other hand, ‘‘had a bad day,’’ as Cardinals manager Oliver Marmol put it.
Happ, who donated the Chicago-flag-themed batting gloves he wore to the Hall of Fame to commemorate the event, made sure of it.
When he stepped into the box in the third, Wainwright again put up two strikes. Then Happ dropped the barrel of his bat on a 1-2 curveball and sent it over the right-field wall.
It was Happ’s 11th career multihomer game and third against Wainwright.
‘‘He’s been so good for so long,’’ Happ said of Wainwright. ‘‘A real legend in our game. And the experience, the at-bats that I’ve had against him, it’s been fun competition.’’
Dansby Swanson, Cody Bellinger, Morel and Gomes followed Happ’s two-out homer with four singles in a row. Wainwright only got out of the inning because of a well-executed cutoff play.
Cardinals outfielder Tommy Edman fielded Gomes’ single into short center on one high bounce and fired home. First baseman Paul Goldschmidt cut off the throw and tossed the ball to third to catch Morel in between bases, but not before Bellinger scored to make it a three-run inning.
The Cubs knocked Wainwright out of the game with back-to-back doubles by Madrigal and Mike Tauchman to lead off the fourth.
Steele pitched through the sixth, allowing one run and striking out eight.
Aside from their stars on the field, the Cubs brought their share of celebrities to London Stadium. Bill Murray, who sat next to former Cubs great Rick Sutcliffe and recently ousted Mayor Lori Lightfoot, elicited a rousing round of applause. Nick Offerman led ‘‘Take Me Out to the Ball Game’’ during the seventh-inning stretch.
Overall, Happ proved to be right about the nature of the game. The only homer he didn’t hit was Swanson’s two-run blast with two outs in the ninth. The Cubs had a season-high nine two-out hits.
There were, however, more literal fireworks. As the stadium speakers launched into ‘‘Go, Cubs, Go’’ after the game, streaks of white and red pyrotechnics erupted over the open-air stadium.
‘‘That sounded good,’’ Ross said of the victory song.
