By ESPNSTAR.com staff
Heading into the game at the Prince Mohammed Stadium 2-1 down following last week's first leg, the Thai Premier League outfit's hopes of making the last four looked dead and buried in the 34th minute after Sinthaweechai Hathairattanakool conceded a penalty.
However, the Sharks goalkeeper made amends by saving a weak effort by Ali Ghalioum and just two minutes later, the visitors went ahead through Pipob On-mo, before Thiago Cunha doubled their lead in the 38th minute with an ingenious chip over Mahmoud Karkar.
Eight minutes after the break, Al Shorta were awarded another penalty when Fode Bangaly Diakite shoved Geilson Soares inside the area and this time around, Oday Jafal stepped up to level the aggregate score.
With neither side able to find another goal in the remainder of the 90 minutes, the match proceeded to extra-time and three minutes in, Ghalioum made amends by netting to make it 2-2 on the night.
Nonetheless, Chonburi refused to give in and netted their third in the 111th minute when Thiago headed home a flick-on by Chonlatit Jantakam, and in the 121st minute, the unlikeliest of victories was completed when the Brazilian completed his hat-trick, lashing an effort past Karkar after beating the offside trap.
Chonburi will now meet Iraqi side Arbil, who defeated Kelantan 6-2 on aggregate, in the semi-finals, while Saudi outfit Al Ettifaq have been pitted against Al Kuwait.
Wednesday's AFC Cup Quarter-final 2nd Leg Results
Al Shorta 2-4 Chonburi (after extra time, 4-5 on aggregate)
Tuesday's AFC Cup Quarter-final 2nd Leg Results