Western Sydney Wanderers coach Tony Popovic on Saturday was still coming to terms with his team's "surreal" victory in the AFC Champions League, after being dismissed a day earlier as a "small side".

"It's a little bit surreal for me," he told reporters after the Wanderers made history by becoming the first Australian side to win the Asian Champions League.

They did it just two years after their club's formation.

A goalless draw against Saudi giants Al Hilal gave them a 1-0 aggregate win in the two-leg final.

"I'm sure it'll hit home in the next few days," said Popovic, a former Crystal Palace player whose team members credit him for their success.

Laurentiu Reghecampf, Al Hilal's Romanian head coach, had on Friday promised that the Wanderers would "stay a small team".

Now they are anything but small, said Popovic.

"Today we are the biggest in Asia. That's the reality," he said, adding the Wanderers had made a "fantastic accomplishment in such a short space of time."

A subdued Reghecampf, however, said his team should have won and blamed the referee Yuichi Nishimura, of Japan.

"Today we played against the other team. We played also against the referee," Reghecampf said.

"I think we were the better team. We don't deserve to lose the game."

The final ended on a sour note when players from both sides squared up after a Saudi player appeared to spit at an Australian opponent.