Zambia came back from two goals down to secure a thrilling 4-2 victory over Iran on Wednesday, taking a giant step towards the knockout stages of the 2017 FIFA Under-20 World Cup in Gabon.

A double from Reza Shekari had the Iranians 2-0 up almost 10 minutes into the second half, but Zambia then shifted up a gear and netted four times in 17 minutes to stun their opponents.

Fashion Sakala, Enock Mwepu, Emmanuel Banda, and Patson Daka netted the goals as Young Chipolopolo made it two wins from two in the group stage, following their opening 2-0 victory over Portugal.

They are just about certain of a place in the second round as the top two sides in each pool, as well as the four best third-place finishers, advance to the knockout stage.

Iran had won their opener 1-0 over Costa Rica and all is not lost for them as they face a final clash with Portugal on Saturday. Zambia will be confident of seeing off the Costa Ricans on the same day.

It did not look good for the Africans early on though, when Shekari missed an open goal with nobody but the keeper to beat, and then did convert a chance six minutes in, after a horrendous mistake from Zambia keeper Mangani Manda.

With time to make his clearance, the keeper passed the ball straight to Shekari, who ran at goal and supplied the finish.

The Iranian forward made it 2-0 early in the second half when his side won a penalty and he easily converted from the spot.

But from then on in it was all Zambia as Sakala collected a pass from namesake and captain Solomon Sakala and blasted the ball home on 54 minutes.

Five minutes later it was 2-2 when Mwepu was given too much time and space, and he supplied a fantastic shot to score.

The turnaround was complete on 65 minutes when Banda found the back of the net, before striker Daka, on as a substitute, grabbed a fourth with 71 minutes on the clock.