Kew Jaliens' late header proved decisive as AZ Alkmaar edged FC Sheriff 2-1 in an entertaining Group E opener the Netherlands.
Johann Gudmundsson put the hosts ahead on 14 minutes, but the visitors always posed a threat and were rewarded when Héctor Moreno fired into his own net midway through the second half. Both sides pressed for victory but it was AZ who prevailed thanks to Jaliens' 83rd-minute winner.
Sheriff needed resilience having failed to win in their last eight European away games, but the manner of the first AZ goal demonstrated why Andrei Sosnitski's side have been so ineffective on their travels. There was little danger when Vladimir Branković passed back to Vladislav Stoyanov but the goalkeeper could only present Gudmundsson with the opener when trying to return the ball to his left-back.
However, the Yellow and Blacks' response was admirable with the equaliser almost instant through André Diedhiou's snap shot while AZ custodian Joey Didulica was also up to the task, keeping out Jymmy França's header following a Benjamin Balima cross. Erik Falkenburg was at the heart of AZ's better moments, flicking on to the roof of the net after a flowing move involving Stijn Schaars and Maarten Martens.
Falkenburg called Stoyanov into action after the restart while França's poked effort dropped onto the roof of net as both sides continued to create chances. Jonathas volleyed just wide from 30 metres with a sensational effort but AZ's failure to prise the second goal was exploited when Baco Nikolić's cross was deflected into his own net by Moreno after 68 minutes.
José Nadson nearly responded in kind with an inadvertent header before Sheriff's best chance to complete the turnaround arrived via Florent Rouamba's drive that Didulica did well to tip over. That intervention proved telling as Jaliens escaped to head in Martens corner and settle the contest.