Ventforet Kofu have a mountain to climb to stay in the Asian Champions League after the J-League second-division outfit lost 3-0 away to Ulsan Hyundai in the first leg of the round of 16 on Thursday.
The 2022 Emperor's Cup champions Kofu had put in a series of commendable performances to top Group H, but came unstuck against the two-time reigning champions of South Korea's K League at Ulsan Munsu Football Stadium.
Kofu will host Ulsan, the 2012 and 2020 ACL champions, at Tokyo's National Stadium on Wednesday in the second leg.
"We had a tame performance away from home so will give every bit of ourselves when we play at home," Kofu forward Kazushi Mitsuhira said.
Joo Min Kyu's header hit the post within nine minutes and Um Won Sang's shot from the angle came off the bar 10 minutes later in a testing start for Kofu, while Ulsan center-back Kim Kee Hee was fortunate to go unpunished after elbowing Mitsuhira from behind before the home side took the lead.
Kofu keeper Kohei Kawata could only parry a cross into the path of Joo, who had an easy job of heading the ball into the unguarded net in the 37th minute.
Former Sagan Tosu player Kim Min Woo was then tripped inside the box by Kofu defender Kaito Kamiya to win a penalty that Joo converted in the 45th minute for his second goal of the night.
Ulsan added their third in the 61st minute when Seol Young Woo combined with Um down the right before finding the far bottom corner to all but put the game to bed.
Kofu substitute Peter Utaka thought he had given his side a lifeline by burying a header three minutes from time, only to see the goal ruled out for offside.
