Ulsan Hyundai booked their place in the semi-finals of the Asian Champions League as Seol Young-woo's volley secured a 1-0 win over fellow South Korean side Jeonbuk Motors on Tuesday to seal a 2-1 aggregate victory.
Seol struck two minutes into stoppage time at the end of the first half to set up a last four meeting next month with either Yokohama F Marinos or Shandong Taishan.
Harry Kewell's Yokohama will host the Chinese Super League outfit in the second leg of their quarter-final on Wednesday, with the J.League side holding a 2-1 lead from the first match.
Ulsan edged a frantic opening 45 minutes in which goalkeeper Jo Hyeon-woo twice denied Jeonbuk with top class saves.
The South Korea international made a reflex stop to keep Tiago Orobo out from close range at the end of a flowing attacking move in the 15th minute while moments later Kim Jeong-hoon pushed Joo Min-kyu's header wide at the other end.
Jo had to be at his best again as the half hour mark approached to frustrate Moon Seon-min after the attacking midfielder was released behind the defence with Jeonbuk increasing the pressure.
However, two minutes into stoppage time Ulsan went in front as Seol met Gustav Ludwigson's cross from the corner of the penalty area with his instep, giving Kim Jeong-hoon no chance as his shot flew into the top corner.
Jo kept out another effort from Tiago seven minutes after the restart, throwing himself at full-stretch to his right to push the Brazilian's shot wide of the target as Ulsan progressed.
Al-Ain, meanwhile, have claimed one of the two semi-final spots in the western half of the draw following their 3-1 penalty shootout win over Cristiano Ronaldo's Al-Nassr on Monday.
The side from the United Arab Emirates will face another Saudi Pro League side in the next round with Al-Hilal and Al-Ittihad facing off later on Tuesday, with Al-Hilal holding a 2-0 lead.
The first legs of the semi-finals will be played on April 16 and 17 with the returns one week later while the final will be played on May 11 and 25.