Former European Cup winners Celtic romped to a 5-0 home rout of Estonians Nomme Kalju in the first leg of their Champions League second qualifying round tie after forward Leigh Griffiths made an emotional return to action on Wednesday.
Red Star Belgrade, who won Europe's premier club competition in 1991, engineered a 2-0 home victory against HJK Helsinki thanks to a Richmond Boakye header and substitute Milan Pavkov's sweeping 90th-minute finish.
Ryan Christie scored a brace for Celtic but Griffiths, who had been out of action since December to deal with personal problems, stole the show when he scored with a brilliant free kick and spurred fans at CelticPark into wild celebrations.
Norwegian defender Kristoffer Ajer headed the 1967 European Cup winners into a 36th-minute lead after Christie floated in an inch-perfect free kick and the provider turned scorer in the 44th with a neat penalty.
Griffiths almost broke down in tears as he celebrated his first appearance for the club in eight months after a sumptuous 45th-minute strike and was mobbed by his teammates as he ran towards the touchline.
Christie made it 4-0 with a superb shot from the edge of the area midway through the second half before Callum McGregor put the icing on the cake with yet another fine strike in the closing stages.
Boakye fired Red Star ahead in the 26th minute after a fine Mirko Ivanic cross before Pavkov, who substituted the Gahanian striker late on, pounced on a poor clearance and drove the ball past Helsinki keeper Maksim Rudakov.
Igor Stasevich inspired BATE Borisov to a 2-1 home win over Rosenborg as he converted a fifth-minute penalty and set up Maksim Skavysh's winner early in the second half after Anders Konradsen had levelled for the visitors.
A Lasha Dvali goal followed by a Davide Lanzafame brace steered Hungarian title holders Ferencvaros to a 3-1 home win over Valetta while Billel Omrani gave CFR Cluj a 1-0 victory against Maccabi Tel Aviv.
Slovenians Maribor ground a 2-1 win over AIK Stockholm after Rok Kronaveter and Sasa Ivkovic netted for the hosts while Dundalk salvaged a 1-1 draw against Azeri visitors Qarabag thanks to a late goal from Patrick Hoban.