Jose Mourinho had been concerned about his players' well-being on a questionable playing surface at the Olimp-2, but following, a shaky opening, United held up well.

If anything the hosts struggled more than the visitors, with Vladimir Granat departing through injury on 17 minutes and Rostov captain Aleksandr Gatskan picking up a 23rd-minute booking that rules him out of the second leg.

Zlatan Ibrahimovic and Henrikh Mkhitaryan combined well for the opener on 35 minutes when the Armenian poked home Ibrahimovic's pass across goal from close range.

Rostov equalised early in the second-half through Aleksandr Bukharov, who got between Phil Jones and Chris Smalling to control a long ball forward from Timofei Kalachev on his chest and shoot past Sergio Romero in the United goal.

After that goal, the hosts took the upper hand in the game but United held on to earn a slim edge ahead of next week's second leg at Old Trafford.

Elsewhere on Thursday, late goals from Nabil Fekir and Alexandre Lacazette ensured Lyon took a commanding 4-2 lead into their second leg against Roma.

The hosts took an early lead through defender Mouctar Diakhaby in the eighth minute but goals from Mohamed Salah and Federico Fazio in the 20th and 33rd minutes turned the game around and had Roma in front at half-time.

Immediately after the break Corentin Tolisso exchanged passes with Lacazette before unleashing a fierce effort from the edge of the area to level the score.

Then, in the 74th-minute Fekir turned and dribbled his way through three defenders before improbably scoring, and in the second minute of added time Lacazette unleashed a rocket into the top corner to seal the win in style.

Borussia Monchengladbach drew at Schalke 1-1 in an all-German matchup.

Jonas Hofmann opened the scoring on the quarter-hour -- the ex-Germany youth international racing onto a Lars Stindl through ball and squeezing his low shot under Schalke goalkeeper Ralf Fahrmann, who could only get a touch before the ball bounced in.

Schalke equalised 10 minutes later with a superb angled strike to the far post from Guido Burgstaller after a Leon Goretzka pass played him in behind the defence.

Claudio Beauvue's 90th-minute goal gave La Liga side Celta Vigo a deserved 2-1 win at home against Krasnodar.

Celta could not break through until five minutes after the break when Daniel Wass' free kick from over 30 yards out crept inside the post. But five minutes later, Viktor Claesson beat Celta keeper Sergio Alvarez at his near post.

With the hosts in control for much of the game, the winner came just as the clock struck 90 minutes, Beauvue sending a glancing header home from Hugo Mallo's cross.

Two weeks after knocking out Tottenham, Gent were on the wrong end of a 5-2 home defeat to fellow Belgian club Racing Genk.

Ruslan Malinovsky opened the scoring with a tremendous curling free kick on 21 minutes, though Samuel Kalu was able to equalise six minutes later, scoring after Jakub Brabec's clearance came back off the crossbar.

But Omar Colley headed home follwing a corner that Gent keeper Lovre Kalinic failed to grab, and it was 3-1 after Mbwana Samatta lashed home. It got worse as Jere Uronen scored Genk's fourth on the counter-attack with the last kick of the first half

Kalifa Coulibaly was able to pull a goal back for the hosts after the hour mark, but Genk keeper Maty Ryan stopped a Jeremy Perbet penalty, before Samatta made Gent pay with his second goal.

Anderlecht, the third Belgian side in the round of 16, came away with a 1-0 win at APOEL in their first leg.

Alexandru Chipciu cut the ball back from the endline for Nicolae Stanciu to score the only goal in the 29th minute with a well-placed shot.

FC Copenhagen scored in the opening minute of their home leg and defeated Dutch giants Ajax 2-1.

Rasmus Falk Jensen got the Danes off to a rocking start when he fired home from an angle before the visitors had even registered a touch.

Ajax then equalised in the 32nd minute through Kasper Dolberg, who volleyed home a Davy Klaassen cross with a defender draped all over him.

But the home side would answer back just before the hour mark thanks to Andreas Cornelius -- the Danish striker rising majestically and heading Peter Ankersen's cross down and past helpless Ajax keeper Andre Onana for the victory.

Olympiakos and Besiktas drew 1-1 at the Karaiskaki Stadium in Greece.

Former Argentina international Esteban Cambiasso got the Greek side off and running in the 36th minute with a pinpoint header of a Karim Ansarifard cross in the box.

Vincent Aboubakar equalised for the visitors on 53 minutes with a fine solo goal after a mis-hit clearance from goalkeeper Nicola Leali fell straight to him.