Popp the hero as 10-man Marinos advance to Asian Champions League final on penalties
Brazilian defender Eduardo scored the decisive spot kick after Marinos' William Popp kept out Kim Min-Woo's effort at the end of an eventful clash at Yokohama International Stadium that saw Yokohama's Takumi Kamijima sent off in the 39th minute.
Marinos had trailed 1-0 from the first leg but raced into a 3-0 lead on the night with the J League side punishing Ulsan's defensive hesitancy.
Asahi Uenaka struck in the 13th minute when the ball bounced off Nam Tae-Hee and behind the Korean defence, allowing the forward to score with a shot across goalkeeper Jo Hyeon-Woo.
Eight minutes later Yokohama doubled their lead, Anderson Lopes shooting low past Jo as the defence stood off the Brazilian to give him the time and space to net.
By the 30th minute Marinos were further ahead, Uenaka turning 25 yards from goal before thumping a long-range strike into the top corner of Jo's goal.
Ulsan looked despondent, with coach Hong Myung-Bo slumped in his seat on the bench, but the Koreans were given a lifeline when Matheus Sales headed in Lee Dong-Gyeong's corner with 10 minutes left in an extraordinary half.
Their fortunes improved further shortly before the break when Kamijima slid in to challenge on the rain-soaked turf, the ball striking the defender on the arm.
Iranian referee Alireza Faghani pointed to the spot and showed a straight red card to Kamijima before Darijan Bojanic stroked in the penalty that levelled the game on aggregate.
Lee then hit the crossbar late in the half and Bojanic saw a strike ruled out for offside following a VAR review soon after the resumption.
Ulsan grew increasingly frantic and Yokohama's desperate defending coupled with Popp's performance in goal, which saw him tip a late effort from Kelvin onto the post, took the game to penalties.
There Popp emerged as the hero when he kept out Kim's effort low to his left and Eduardo converted to take Marinos through to their first Asian Champions League final.
Kewell's team will face an Al-Ain that eliminated Saudi Arabia's Al Hilal on Tuesday, with the first leg in Japan on May 11th and the return in the UAE two weeks later.