A last-gasp goal by Gustavo Manduca gave Champions League surprise package APOEL Nicosia a 2-1 win over Portuguese giants Porto here on Tuesday and sent them back to the top of Group G.
Manduca's 90th-minute goal restored the hosts' lead, which they had seen erased by an 89th-minute penalty from Porto striker Hulk.
The hosts' in-form marksman Ailton had given them the lead with a penalty in first-half injury time.
APOEL's win pushes them tantalisingly close to becoming the first Cypriot side to qualify for the knockout stage of European club football's showpiece tournament.
Ailton's third goal in four group matches was slightly cruel on the visitors, who had enjoyed the larger share of possession.
However, he earned it all by himself as he burst into the box only to be brought down by Eliaquim Mangala, leaving the referee no option but to point to the spot. Ailton despatched the spot-kick clinically.
Porto had rarely threatened a breakthrough, with only two efforts by Brazilian striker Hulk causing any concern for the home defence, but goalkeeper Urko Pardo was equal to the task on both occasions.
Indeed it was Ailton, who had gone closest to breaking the deadlock prior to the penalty, when his header hit the post in the 20th minute.
The second half saw the hosts continue to rely on the counter-attack and with 10 minutes remaining, coach Ivan Jovanovic replaced the impressive Ailton with Bosnian defender Sanel Jahic.
Just as APOEL thought they were close to returning to the top of the group, Hulk intervened, but the hosts showing the character they have displayed throughout the group stage by replying immediately.
APOEL skipper Constantinos Charalambides found space down the right and he put in a superb cross to the far post, where Manduca made no mistake to send the 20,000-plus spectators crazy with joy.