Uzbekistan moved into pole position to qualify for a first World Cup when Ulugbek Bakaev struck the only goal to grab a precious 1-0 win away over Iran in qualifying on Wednesday.
The forward darted ahead of his marker to poke home Server Djeparov's brilliant free kick in the 71st minute to silence the passionate crowd in Tehran and dent the hosts' chances of a place in Brazil.
The Uzbeks went top of Group A of Asian qualifying with eight points from five matches, one ahead of South Korea, Qatar and their beaten opponents with only the top two guaranteed a place in Brazil.
The Iranians had been the better side for most of the first half but throughout qualifying they have found goals hard to come by and Wednesday was no different.
The home side, who had scored only twice in their four matches in the group, thought they had taken the lead in the 12th minute through Mohammad Nori but the midfielder was called back from celebrating his strike after a team mate strayed offside.
The early energetic display would have pleased Iran coach Carlos Queiroz, who was restricted to a place in the stands after being sent off in the 1-0 win over South Korea last month.
But the Uzbeks were defending bravely and with Asian Player-of-the-Year Djeparov providing a series of dangerous set pieces the visitors always looked a threat.
Queiroz introduced Karim Ansari at the break and he almost had an instant impact but his steered shot from the edge of the area flashed just wide two minutes into the second half.
But as the match wore on the technically superior visitors took control through midfield and grabbed the lead inevitably from a Djeparov free kick.
The much-travelled playmaker whipped in an inswinging set piece with his left foot from close to the touchline which Bakaev poked home from inside the six yard box with the Iran goalkeeper stuck on his line.
Iran pressed in the final stages and had the ball in the back of the net for a second time but substitute Milad Nouri's 91st minute effort was ruled out again for offside.
The win gave the Uzbeks revenge for their 1-0 home loss to Iran in the opening match of the group in June which they had controlled throughout only to concede the winner in the 94th minute.
The Uzbeks next face bottom-placed Lebanon at home in March with Iran not in World Cup action again until June when they play their final three matches.