Walker Zimmerman wagged his left pointer finger in the air from where he lay sprawled out on the ground. He shook his head and yelled, “No, no, no, no, no!” But it was to no avail. The referee was already pointing to the penalty spot.

The United States had been leading Wales by the narrowest of margins in the teams’ return to the World Cup when, with roughly 10 minutes remaining before second-half stoppage time, Zimmerman slid into the legs of Welsh superstar Gareth Bale and sent him tumbling to the grass.

Soon, Bale was on his feet again, blasting his penalty kick into the right corner of the net, scoring the goal that helped Wales snatch a 1-1 draw Monday that may have suited both teams but will have really pleased only one.

It was a cruel ending for the United States, which was returning to the biggest stage in men’s soccer for the first time in eight years and looked to be in control for much of the match after being staked to a first-half lead by forward Tim Weah. But it will have to do, for both of them, for now.

“We’re disappointed with the nature of how the game played out,” Zimmerman said, “having a great first half, getting the first goal, and being in a position with less than 15 minutes left to walk away with 3 points.”

The match felt, in some ways, like a collision between bright, hopeful ideas and long-seasoned pragmatism. The United States, the second-youngest squad in the tournament, looked lively for large stretches of the match. Tim Ream, playing his first game for the U.S. since last year, started the game at center back and formed an effective partnership with left back Antonee Robinson, his club teammate with Fulham in the English Premier League. The three American midfielders circulated the ball with intent. The Americans, though, lacked the polish to finish off some of their chances.

“It’s disappointing for sure after such a good start,” American star Christian Pulisic said. “We got the goal we needed, and I guess we just dropped off in the second half.”

After struggling through a meek first half, the Welsh made a series of sensible adjustments, most crucially inserting Kieffer Moore, a 6-foot-5 striker, into the game as a target forward. Because of his presence, they could employ a direct style of attack — stretching the field, flinging balls into the U.S. penalty area — that immediately put the Americans under more pressure.

Even the game-turning penalty, in Zimmerman’s estimation, was the result of some veteran savvy. He said after the game that he did not see Bale come across his path in the 18-yard box as he prepared to clear the ball as it bounced in front of him. He added that he thought Bale had intentionally positioned his leg to draw the foul.

“I think it was one of those where he probably just puts his leg not for the ball but to try to get in the way of me hitting the ball,” Zimmerman said. “Clever move. Wish I would have seen him out of the corner of my eye on trying to clear the ball. It was instinctive. It was quick. Little bit frustrated with that.”

The Americans will have to quickly regain their bearings. They play England — which defeated Iran 6-2 earlier Monday to take the lead in Group B — on Friday night.

With Wales bunkered in front of its goal, employing five defenders and stacking the rest of the team close by, the Americans, who enjoyed two-thirds of the possession in the first half, spent much of that time easing the ball from side to side, trying to find an opening, waiting for the Welsh to slip up or doze off for a moment.

The moment came, finally, in the 36th minute. Pulisic received the ball on the run and surged through the heart of the Welsh defense, dragging two defenders with him. Simultaneously, Weah was making a slashing run toward the goal from the wing. Pulisic slotted a perfectly weighted pass into the penalty area, where Weah stutter-stepped and flicked the ball into the net with the outside of his right cleat.

Weah then wheeled away from the goal and slid toward a corner flag, where his teammates engulfed him in celebration.

“It’s a great feeling,” said Weah, whose father, George, won a FIFA World Player of the Year award and a Ballon d’Or but never appeared in a World Cup. “He’s living this moment through me.”

After making its practical adjustments at halftime, Wales became the aggressor.

Before Bale’s goal, the Welsh’s best scoring chances arrived around the 64th minute, when Ben Davies headed a ball that seemed to be destined for the goal until American goalkeeper Matt Turner pushed it over the crossbar. On the ensuing corner, Moore drilled a header of his own over the net.

Even then, the Americans seemed to be cruising toward a crucial opening victory.

Until Bale stepped up, as he so often does, to steal away the spotlight.

“Sometimes you’ve just got to shrug it off and roll with it,” Zimmerman said. “It happened, move forward. There’s not much time to dwell on it with how quickly this tournament happens.”