Western Sydney Wanderers delivered a seismic shock Wednesday when they sent title-holders and hot tournament favourites Guangzhou Evergrande crashing out of the AFC Champions League.

The Australian debutants survived despite losing the quarter-final's second leg 2-1, as they went through on away goals following last week's 1-0 upset win in Sydney.

The surprise victory means Tony Popovic's side become only the second Australian team to reach the AFC Champions League semi-finals, after Adelaide United in 2008.

Guangzhou's World Cup-winning coach Marcello Lippi, banished to the stands after angrily confronting last week's referee, sat with a lit cigar as his title defence went up in smoke.

The Wanderers will next face last year's runners-up FC Seoul, whose goalkeeper Yu Sang-Hun saved three penalties in a dramatic shoot-out to deny Korean rivals Pohang Steelers.

Guangzhou were a weakened side, missing three players through suspension as well as Italian maestro Lippi, who was punished for his angry reaction after two late red cards in Sydney.

But Italian forward Alberto Gilardino came within inches for the Chinese champions when his cushioned near-post volley rebounded off the crossbar from a tight angle.

Elkeson should have levelled the tie at 1-1 on aggregate after he was sent crashing the penalty area by Western Sydney's Iacopo La Rocca.

However, the big Brazilian's soft penalty was parried by Wanderers goalkeeper Ante Covic, who dived the right way to keep the visitors in front.

The mood was darkening at Tianhe stadium and it became bleak when home goalkeeper Zeng Cheng up-ended Mark Bridge, and Tomi Juric coolly slotted the penalty on 57 minutes.

But Guangzhou's response came swiftly and just four minutes later, Gilardino's knock-down was smashed home by his compatriot Alessandro Diamanti to make it 1-1 on the night.

Guangzhou poured forward but Gilardino, Elkeson and Dong Xuesheng all let good opportunities slip as the champions' title defence ebbed away.

Elkeson finally hit the net a minute into injury time but there was to be no fairytale comeback for the financially well-endowed team tagged "the Manchester United of Asia".

Meanwhile in Seoul, 210 minutes of goalless football gave way to an extraordinary shoot-out when 'keeper Yu saved kicks from Hwang Ji-Soo, Kim Jae-Sung and Park Hee-Chul.

Kim Jin-Kyu also missed a penalty for FC Seoul but Everton Santos, Osmar Barba and Mauricio Molina converted for the 2013 runners-up to send them through to the last four once again.

In the other semi-final, Saudi Arabia's Al Hilal will meet 2003 AFC Champions League winners Al Ain of the United Arab Emirates, with the first leg in Riyadh on September 16.