Europa League: Riga 0 Celtic 1
Mohamed Elyounoussi's last-gasp strike ensured Celtic avoided another European nightmare as they scraped to a 1-0 win over Riga.
The Hoops were looking to recover some continental pride in Latvia following last month's humiliating Champions League exit at the hands of Ferencvaros.
Yet it was another frustrating night for Neil Lennon as his team again laboured through the motions before edging their way into the Europa League play-offs.
Odsonne Edouard was back on duty after sitting out the weekend win over Livingston but the Frenchman showed little enthusiasm for the task of spearheading Celtic's attack. And it was the man who replaced him with eight minutes left, Elyounoussi, who grabbed the all-important last-minute goal to seal victory.
Les Bleus under-21 ace Edouard was supposed to be back refreshed having missed the Livi clash after complaining of tiredness on the back of a hectic schedule for club and county.
But he hardly exerted himself during some pretty lethargic opening exchanges at the Skonto Stadium.
The Scottish champions are well used to teams parking the bus, but Riga took it one step further after positioning a pair of double-deckers behind one of the goals so a couple dozen home supporters could cheer on their side.
They were off their seats after 21 minutes as Celtic got themselves so out of shape that the Latvians raced clear on a three-on-one.
Nir Bitton rescued the Hoops with a vital block before Vladimirs Kamess could roll in a team-mate but Lennon could be forgiven for having worrying flashbacks to last month's Champions League catastrophe.
Olivier Ntcham had a 25-yard drive tipped over by Roberts Ozols while a better connection might have seen Bitton net after Shane Duffy climbed high to nod down Christie's up-and-under.
Edouard, having ambled around for most of the first half, suddenly shrugged himself into action as he slid McGregor in behind the defence but Ritvars Rugins covered to deny Frimpong a tap-in at the back post.
Half-time offered Lennon the opportunity to remind his men they had no margin for error in this one-off tie.
Portuguese ref Fabio Verissimo was lenient as he let Kamess off with a yellow after a rake of the studs down Scott Brown's Achilles.
Albian Ajeti had made a clinical start to his Hoops career with a goal every 40 minutes so far, yet he someone failed to convert from a yard out just moments after replacing Ntcham.
In the 90th minute Frimpong swept a cross into the box for the Norwegian to angle home a precious winner.