SEOUL/POHANG (Yonhap) -- The Pohang Steelers picked up their first loss at the Asian Football Confederation Champions League Wednesday after falling 1-0 to Australian club Sydney FC at home.

At Pohang Steel Yard in Pohang, a port city 360 kilometers southeast of Seoul, the hosts failed to overcome Sydney midfielder Chris Naumoff's goal in the first half and surrendered the top spot in their group to the Australian club.

Sydney, the runner-up in the Australian A-League last season, now have two wins and one loss in Group H of the AFC Champions League, while Pohang are 1-1-1 in the same group.

Pohang, three-time champions of the AFC Champions League, came up with a 4-2-3-1 formation. While striker Lazar Veselinovic started up front, South Korean attacking midfielders Moon Chang-jin, Sim Dong-woon and Kang Sang-woo led the K League Classic club's offense.

But Pohang's offense wasn't threatening. Instead, they allowed a couple of dangerous moments to Sydney from the early phase, including Australian forward George Blackwood's header that went over the net in the 16th.

While exchanging shots, Sydney scored the opening goal in the 42nd, when Blackwood's pass found Naumoff, whose right-foot strike beat Pohang goalkeeper Shin Hwa-yong.

Looking for an equalizer, Pohang replaced Veselinovic with new striker Yang Dong-hyun in the second half, but the frequent pass mistakes in the midfield failed to smooth their attack. Yang, who joined from domestic club Ulsan Hyundai FC, fired a couple of threatening shots in the later end of the match, but failed to open the net.

In the extra minutes, Pohang were given a corner kick and a couple of chances from the flank, but second-half substitute Jung Won-jin's shot and Sim's strike both went wide.

Earlier in the day, FC Seoul beat China's Shandong Luneng 4-1 to stay perfect in the ACL.

At Jinan Olympic Sports Centre in Jinan, China, Seoul collected their third straight victory at the ACL, thanks to a double from their Brazilian striker Carlos Adriano. The victory secures Seoul's top rank in Group F.

Seoul, the reigning champion of the Korean Football Association Cup, had been the hottest attacking club at Asia's premier club tournament before playing against Shandong. The K League Classic side scored 10 goals in their last two group contests against Thai league winners Buriram United and Japanese champion Sanfrecce Hiroshima. Adriano had scored seven of those 10 goals.

Despite losing their domestic league opener 1-0 to Jeonbuk Hyundai Motors, Seoul and Adriano proved their offense still hasn't cooled down, at least in the ACL.

Seoul, led by head coach Choi Young-soo, started the match with a 3-5-2 formation, putting their formidable foreign strikers Adriano and Dejan Damjanovic up front.

Seoul, eliminated in round 16 at last year's ACL, went up on the board first in the 27th minute after Adriano tucked in his Japanese teammate Yojiro Takahagi's cross.

Finishing 1-0 in the first half, Seoul allowed an equalizer in the 61st minute when Jucilei headed down Shandong team captain Hao Junmin's left-footed cross, while midfielder Go Yo-han failed to mark the Brazilian midfielder.

However, Seoul's offense started to explode from that moment, scoring three goals in six minutes.

In the 65th minute, Go washed off his fault in Shandong's equalizer with a left foot strike that made the score 2-1. Three minutes later, Seoul's Montenegrin striker Damjanovic stepped in as a goal scorer after beating Shandong goalkeeper Wang Dalei with his left foot to double the lead. In the 71st minute, Adriano bagged his ninth goal of the tournament after tapping Damjanovic's cross.

"I'm happy to keep the pride of the K League," Seoul head coach Choi said after the match. "I think our offensive mindset from the beginning to end gave our opponents difficulty throughout the game."

Seoul and Shandong will face each other again on April 5 at Seoul World Cup Stadium in Seoul.