Manchester United laboured to a 1-0 Europa League victory over Zorya Luhansk at Old Trafford as Zlatan Ibrahimovic headed home in the second half to seal the points for the below-par hosts.
United struggled to create clear-cut chances against their well-organised Ukrainian opponents, but did come agonisingly close to taking the lead after 20 minutes when Marcus Rashford thundered an effort off the underside of the bar.
But it was Zorya who mustered the first real threat of the evening with only five minutes gone when Iwan Petriak got down the left and crossed low for Zeljko Ljubenovic, who blasted high over the bar from 16 yards.
Marouane Fellaini then headed a Juan Mata corner over the top before the visitors created another flicker of danger as Igor Chaykovsky crossed threateningly to force Chris Smalling into defensive action.
United were struggling to inject any real pace into their play, with manager Jose Mourinho frustrated on the touchline as an Ibrahimovic drive crashed off a defender and, as the half-hour approached, Juan Mata just failed to find Paul Pogba with a chip into the area.
The home side tried to up the pace as the half drew towards a close at a muted Old Trafford, with Ibrahimovic blasting a 25-yard free-kick into the wall and Mata heading a fine Pogba cross just wide.
Zorya were grateful to see a powerful Fellaini header from a corner bounce into the ground and over in the final seconds -- but United began the second half sluggishly and were almost made to pay when a cross from the visitors' right evaded everyone.
Fellaini's curling effort from edge of the area was easily blocked, while soon afterwards a low Jesse Lingard cross from the same side was straight at the goalkeeper.
After Eric Bailly was booked for a clumsy challenge shortly after the hour, home goalkeeper Sergio Romero made the first save of the game when he pushed away Paulinho's curling shot.
Mourinho brought Wayne Rooney into the fray in place of Lingard -- and within moments he was involved in the move that brought the 69th-minute United breakthrough.
Timothy Fosu-Mensah found space on the right and pulled the ball back towards Rooney, whose miscued effort looped into the air and was headed in by Ibrahimovic at the far post from a couple of yards out.
Mourinho brought Ashley Young and Anthony Martial as his side saw out the final 15 minutes with few alarms to seal their first win in this season's competition.