Celtic eased past Stjarnan in the return leg of their Champions League second qualifying round tie, but not before an early scare against the Icelandic part-timers.
The Hoops travelled to the tiny Samsungvollur stadium with a 2-0 advantage from last week's first leg in Glasgow but found themselves under some unexpected pressure after only six minutes when Olafur Karl Finsen shot the home side into a shock lead.
However, midfielder Nir Bitton eased the nerves when he levelled in the 32nd minute from a Stefan Johansen corner. When defender Charlie Mulgrew fired in a second early in the second-half it was all over as a contest with late goals from substitute Leigh Griffiths and Johansen making it 4-1 to see the Hoops through 6-1 on aggregate.
Kazakhstani side Astana caused one of the upsets of the round, overturning a first-leg deficit against 2014-15 group-stage qualifiers Maribor.
Astana won the game 3-1 (and the tie 3-2 on aggregate) thanks to goals Baurzhan Dzholchiev, Roger Canas and Patrick Tvumasi. Despite being reduced to 10 men after Canas was dismissed for his second bookable offence in the 67th minute, the Kazakhstani's held on and will face HJK Helsinki in the next round.
Steaua Bucuresti had their two-goal first leg cushion to thank after Slovak Super Liga champions Trencin walked away with a surprise 3-2 win in Romania.
Steaua progress 4-3 on aggregate to play Partizan Belgrade in the next round, but were pushed all the way by the plucky Slovakian side.
Goals from Wesley and Matus Bero in the opening 21 minutes brought the tie level, before Muniru Sulley handed Steaua back the aggregate lead on 57 minutes. The tie seemed to be as good as over once Gregory Tade slotted a penalty and Trencin were reduced to ten men following Milan Rundic's red card.
But, six minutes from time, Wesley netted again for the visitors -- setting up a tense finale which Steaua Bucuresti narrowly scraped through.
In Luxembourg, Dinamo Zagreb made up for last week's shock 1-1 draw to eliminate Fola Esch 4-1 on aggregate.
Marko Pjaca bagged a first-half brace for the Croatians before substitute Marko Rog's goal made sure of the result 15 minutes from time.
League of Ireland champions Dundalk were unable to overturn BATE Borisov's 2-1 aggregate lead in scoreless draw at Oriel Park.
Just like the first leg in Belarus, the match was a heated affair with eight yellow cards being handed out over the course of the match.
David McMillan came closest to breaking the deadlock for the Irish side, while keeper Gary Rogers did well to turn an Igor Stasevich shot on to the bar.
Meanwhile in Hungary, Welsh side The New Saints pushed Videoton all the way into extra-time before finally falling to a 2-1 aggregate loss.
In stiflingly hot conditions, Matty Williams levelled the tie in the 78th minute before Adam Gyurcso broke TNS hearts with a goal in the 107th minute of the match.
"The players were outstanding tonight," TNS manager Craig Harrison told the BBC.
"We worked out where their weaknesses would be and where our strengths would be and the lads were absolutely outstanding, every single one. I think we have been very very unlucky."
In Wednesday's other matches, Azerbaijani champions Qarabag defeated Rudar Pljevlja 1-0 on aggregate thanks to Reynaldo winner, while Lech Poznan cruised to a 3-0 aggregate win over FK Sarajevo with Barry Douglas netting the second leg's only goal.
Information from PA Sport was used in this report.