A decisive strike by Chelsea's Christian Pulisic seven minutes into the second session broke Iranian hearts while helping USA to a 1-0 win in a match which drew interest on and off the field considering the long-standing political hostilities between the two countries.
On Tuesday at the Al Thumama Stadium, the Chelsea striker scored the only goal of the match in the 43rd minute. Pulisic's lone strike took them into the last-16 stage where they will take on The Netherlands on Saturday.
The US, returning to the World Cup for the first time in eight years, thus finished with five points with one win and two draws and sailed into the knock outs as group runners up and will face The Netherlands, the winners of Group A.
The USA have two draws, 1-1 with Wales and 0-0 against England. Iran, who were thrashed 6-2 by England but recovered to beat Wales 2-0, finished with three points, for the 2-0 win over Wales, who were returning to the World cup after a 64 years absence lost all their league matches.
For Iran, who never have gone past the group stage, the wait to play in the knockout will move to another World Cup. England topped the group after a 3-0 win over Wales and will take on African Cup Champions Senegal, the Group A runners up in the knockout stage.
The Americans had most of the ball possession in the first half and completely dominated Iran who, from the first minute, looked to be playing for the draw that would have almost certainly put them through.
Although Coach Gregg Berhalter was under so much pressure from the wings the lack of a final ball to break open the defence was sadly missing. But the US did score a goal but Tim Weah was pulled offside in the first half.
After a few close calls West McKennie's long diagonal finds Sergino Dest, who comes from behind the defence to head across goal for Pulisic to bundle home. A crucial strike and a courageous finish, and the Chelsea winger got injured himself in the process.
It's a brave effort as Ali Beiranvand comes out to clear. The keeper's knee smacked into Pulisic and he was badly hurt and was being treated. Thereafter in the second half Iran and USA tried to break open the defence but without any results with the US making its way into the last 16 and Iran making their early exit.
"In the first half we showed what we can do, soccer wise. We had a really good first half. Second half we showed what we could do determination wise. The guys grinded, gave every single ounce and we are undefeated going into the next round," USA coach Gregg Berhalter said while speaking to BBC One.
Berhalter gave Pulisic a pat on the back for his courageous goal with the striker getting injured while scoring a goal. "No update on his status. But it's a wonderful thing when one of your best players is also one of the most hard working.
He's certainly that. I can't say enough positive things about Christian," said Berhalter. "With this new injury time, counting every second it's stressful. I think I have less hair on my head now! But we'll take it and move on and go to battle against Holland."