Celtic took a step closer to the Champions League group stages with a 2-1 win over Finnish side HJK Helsinki on Wednesday night, but the goal conceded leaves Neil Lennon's men with plenty to do next week in Finland.
The Hoops were made to pay for early profligacy less than two minutes into the second half when Rasmus Schuller fired the visitors ahead.
Parkhead striker Gary Hooper levelled in the 54th minute, before defender Charlie Mulgrew headed the winner seven minutes later.
Lennon will rue the moment of slackness which could ultimately end his Champions League dream, but the Parkhead boss will be heartened by the way his players reacted in adversity.
Fenerbahce needed a last-minute goal from Bekir Irtegun to avoid an embarrassing first-leg defeat to Romanian side Vaslui .
The visitors took a shock lead through Liviu Antal's breakaway goal in the 75th minute and looked set to take their advantage into the second leg. But Irtegun converted Alex's corner just as the clock ticked into stoppage time to earn the Turkish side a 1-1 draw.
Dieumerci Mbokani scored twice as Belgian champions Anderlecht cruised to a 5-0 win over Lithuanians Ekranas. Tom De Sutter, Kanu and Milan Jovanovic were also on target as the hosts produced a dominant display.
Belgium's other representatives, Club Brugge, failed to register an away goal as they played out a goalless stalemate against Copenhagen in Denmark.
Basle won 1-0 away to 10-man Molde. Davy Claude Angan was sent off in the 27th minute, but Basle had to wait until the 79th for the only goal, courtesy of substitute Jacques Zoua.
Substitute Ibrahim Sidibe scored for both sides as Debrecen drew 1-1 away to BATE Borisov, the Senegalese forward turning the ball into his own net in the 93rd minute.
Fatos Beqiraj's 14th-minute goal gave Dinamo Zagreb a 1-0 win away to FC Sheriff, while Vouho's first-half strike saw AEL past Partizan Belgrade by the same scoreline.
Helsingborg enjoyed a comfortable 3-0 win away to Slask Wroclaw in Poland. Alfred Finnbogason gave the Swedes a half-time lead which was added to by Christoffer Andersson and Daniel Nordmark.
Elsewhere, CFR Cluj beat Liberec 1-0, Hapoel Kiryat Shmona were 4-0 winners over Neftchi, with Bryan Gerzicich scoring twice, while Maribor beat Dudelange 4-1.