Morteza Pouraliganji of Iran celebrates after the match against China in FIFA 2018 World Cup Qualifier on March 28, 2017 in Tehran, Iran. [Photo/VCG]

SYDNEY - Iran took a significant step towards qualifying for next year's World Cup finals with a 1-0 win over China on Tuesday that pushed Marcello Lippi's team closer to the brink of elimination.

Mehdi Taremi scored the only goal of the game less than a minute after halftime as Iran remained unbeaten in the third round of Asia's qualifying tournament for Russia 2018.

Carlos Queiroz's team moved on to 17 points from seven games, four clear of second-placed South Korea, who got their own campaign back on track with a 1-0 win over Syria that reduced the mounting pressure on coach Uli Stielike.

China, however, failed to build on last week's morale-boosting win over Stielike's side in front of a packed-out Azadi Stadium. They remain fifth in the group, eight points adrift of the Koreans, who occupy the second of the two automatic qualifying berths.

"The experience of the last two rounds has shown that there is still room for us to improve," said Lippi, who took over as China coach in October. "They were two good matches, but when facing a strong side like Iran our defence needs to improve."