Mason Greenwood scored twice as Marseille injected life into their Champions League campaign with a 3-2 victory at Union St.-Gilloise.

Roberto De Zerbi's Ligue 1 title hopefuls had won only two games in the competition before Tuesday night's trip to Brussels and time was running out if they were to force their way into playoff contention, with Union also boasting two victories and the historic head-to-head bragging rights, having beaten Marseille 4-2 in the Inter-Cities Fairs Cup in 1962.

The first goal between the clubs in 63 years arrived after just five minutes of action at Lotto Park. As David Hubert's Union pushed forward confidently, Israeli midfielder Anan Khalaili received the ball from Rob Schoofs on the edge of the box before sending a left-footed drive past Gerónimo Rulli.

It only took Marseille 10 minutes to level, though, Igor Paixão slotting home his fourth Champions League goal by pouncing on a shot spilled by Kjell Scherpen after intricate passing had bamboozled the Belgian champions' backline.

If Paixao has been Marseille's talisman on the continent then Greenwood's goals have kept them flying high in Ligue 1 and he ended a three-game dry spell in all matches to hit his 12th of the season at a crucial point heading into halftime.

The former Manchester United striker did most of the running to get the ball forward on a rapid counter-attack by Les Olympiens before picking his spot when veteran hitman Pierre-Emerick Aubameyang found him lurking near the penalty spot.

It was lucky No. 13 for Greenwood soon after the break as he burst into the box, shimmied to lose his man and smashed in at the far post.

Khalaili kept the contest alive with Union's second in the 70th minute. After coolly controlling a speedy cross from the left wing, he rifled past Rulli with his right boot.

Kevin Mac Allister did not want Khalaili to be scoring at home alone but his scuffed close-range equaliser was ruled out.