Last season's bottom club moved above Jeonbuk Hyundai Motors, who did not play this weekend, thanks to a Kim Myung-joong header eight minutes into the second-half.

Despite the team's fourth win in five games, coach Lee Kang-jo played down their recent form.

"It is a good start and nothing more. We are top because Jeonbuk have played a game less," he said.

"We are eager to reach the play-offs but I am worried that we don't have the squad to cope with injuries."

The loss was Incheon's first of the season.

Champions Suwon Samsung Bluewings picked up their first win of 2009 to move off the bottom of the table with a 2-0 triumph over Busan I'Park.

Lee Sang-ho headed home his first league goal for the club since his switch from Ulsan when he connected with Eduardo's cross. The Brazilian striker then turned provider to poacher to seal the points in the final minute.

"This is the result that our fans have been waiting for for a long time," said Suwon boss Cha Bum-keun.

"Now we need to make sure that we keep moving in the right direction."

Elsewhere, FC Seoul were held to a 1-1 draw by Gyeongnam FC. Brazilian star Indio fired Gyeongnam ahead in style with a free-kick on the hour mark but Seoul's Montenegrin marksman Dejan Damjanovic netted from close range with 10 minutes remaining to earn a share of the spoils.

A last-minute equaliser from Daejeon Citizen denied Ulsan Hyundai Horang-I their first win of the campaign as the two teams drew 1-1, while Daegu beat Jeju United 2-1.