DOHA, Qatar – Christian Pulisic scored the goal that beat Iran 1-0 and took the United States into the knockout stage of the World Cup on Tuesday night, and that's really all anyone needs to know.

All Gregg Berhalter's Americans showed heroic spirit and fierce resolve at Al Thumama Stadium, but Pulisic put his body on the line in the most devil-may-care way to secure the only goal of the game.

On 38 minutes, nearing the end of a first half that had brought little but frustration in the face of Iran's ill-advised dedication to total defense, Weston McKennie got the ball in midfield and spotted right back Sergiño Dest speeding forward on the flank.

McKennie's floated ball was nodded across the face of goal by Dest, and Pulisic won the foot race to steer it home from a few yards out.

The 24-year-old American, already a Champions League winner with Chelsea and seemingly destined for the top since he first broke into the national team squad as a teen, collided heavily with Iran goalkeeper Alireza Beiranvand and lay winded on the turf for several minutes.

Just before the break they could have put the contest further beyond Iran's reach on a pair of breakaways, one where Josh Sargent and Timothy Weah failed to connect and another where Weah put the ball in the net, but was ruled offside.

Iran could no longer sit back and hold on, and pressed men forward as they sought the equalizing goal needed to put their country through to the elimination rounds for the first time in history.

Perhaps seeing the folly of Iran head coach Carlos Queiroz's ultra-cautious tactics, the Americans weren't sitting on the lead, despite Iran's proven effectiveness on the break, with speedy forwards Mehdi Taremi and Sardar Azmoun ready to pounce.

It was a different Iran now, No longer were there 10 players behind the ball as a defensive wall.