Both sides struggled in a cagey opening that saw Buriram United’s Peter Zujl take aim, only to slice his effort from outside the area well wide of the goal.

As the half moved beyond the midway point, however, Ulsan began to test visiting goalkeeper Etheridge.

The Philippines international gathered Lee Hui-gyun’s attempt from distance at the second attempt while, in the 27th minute, he dropped to his right to block Lee Jin-hyun’s shot after the Ulsan midfielder burst into the penalty area, with Marcao heading the rebound wide.

Kingley Schindler thought he had given the Thai champions the lead nine minutes before the break when he slid his low shot past Moon Jung-in, only for the assistant referee to raise his flag for offside moments after the ball had crossed the line.

Marcao thumped his left-footed effort over the bar four minutes into the second half and, soon after, he directed Park Min-seo’s corner from the right onto the top of the Buriram United crossbar with Etheridge beaten.

Etheridge was quick enough across his goal line to pluck Seo Myung-guan’s header out of the air as Ulsan increased the pressure.

But it was the visitors who should have gone ahead in the 64th minute when Guilherme Bissoli fed the ball to Robert Zulj and his return pass released the Brazilian into space inside the Ulsan penalty area, but the striker shot over the crossbar.

Etheridge ensured the visitors took a point back to Thailand when he pushed Heo’s goal-bound header over the bar following Lee Chung-yong’s in-swinging cross from the left side of the penalty area with a little more than two minutes left on the clock.