Western Sydney opened its Asian Champions League (ACL) campaign in dismal fashion with a 4-0 group-stage drubbing by Japanese giants Urawa Red Diamonds.

It came on the same night a depleted Brisbane Roar held Thailand’s Muangthong United to a draw.

Three days after their drought-breaking A-League Sydney derby win, a second-string Wanderers side conceded two rapid-fire, second-half goals from Japanese internationals Shinzo Koroki and Tadanari Lee.

Tomoaki Makino and Rafael then landed the killer blows at Campbelltown Stadium on Tuesday night to deliver the 2014 champions their heaviest ACL loss across three campaigns.

Coach Tony Popovic catered for a short three-day turnaround, along with this Saturday’s trip to Perth, with six changes to his starting XI, thrusting untested teenaged striker Abraham Majok into the mix.

It was a baptism of fire for the 18-year-old Kenyan-born South Sudanese, who led the line on club debut against one of Asia’s top teams just five months after last playing in the NPL 2 for Mt Druitt Town Rangers.

His offside goal aside, Majok battled to make a dent in the Reds, who deployed close to their strongest line-up but showed a lack of polish, expected of a team yet to start their domestic season.

Meanwhile, the Roar held Muangthong United to a scoreless draw at home.

Brisbane, playing with a raft of key players missing due to injury, had to rely on a string of strong saves from Jamie Young on to keep the Thai Premier League champions at bay.

The Roar were warm favourites to win against Muangthong. Photo: AAP

The Roar were warm favourites to win, but it was never going to be an easy task against Muangthong – six of its starting players featured for Thailand in November’s 2-2 World Cup qualifying draw against the Socceroos.

Former La Liga striker Xisco – who transferred late last year to the Thai club – was a constant threat up front for Muangthong, but stand-in captain Jade North and his rookie defensive partner Cameron Crestani thwarted him and his teammates at every turn.