Porto and Celtic crashed out in Champions League qualifying but last season’s semi-finalists Ajax managed to advance to the play-off round.
Porto – who had featured in the Champions League group stage in each of the last three campaigns, including a run to last season’s quarter-finals – were upstaged 3-2 by visiting Krasnodar on Tuesday.
Krasnodar blitzed Porto with a three-goal first half thanks to Magomed Suleymanov’s brace as the Russian side prevailed on away goals after a 3-3 draw.
Scottish champions Celtic were denied a play-off berth by Cluj, whose 4-3 victory on the night in Glasgow secured a shock 5-4 success across two legs.
Celtic led the second leg 3-2 after 76 minutes but Billel Omrani and George Tucudean struck inside the final 10 minutes to silence Parkhead and give the Romanian outfit a memorable victory.
Captain Dusan Tadic was at the double as Erik ten Hag’s Ajax held on to beat PAOK 3-2 in Amsterdam, where the Eredivisie holders escaped 5-4 on aggregate.