Manchester United have a difficult rearguard action ahead of them after going down to 10 men in the first half of their Premier League clash with Manchester City at the Etihad Stadium.

United defender Chris Smalling picked up an early booking for impeding Joe Hart, before bringing down James Milner with a wild slide to receive his marching orders, but the visitors hung on at 0-0 until the break.

City goalkeeper Hart was forced into an early save to deny Marcos Rojo, but the United defender had been in an offside position after meeting a free kick from Angel di Maria.

Sergio Aguero had the game's first real chance after driving into the United box with eight minutes on the clock, but his effort was straight at David de Gea, who pushed the Argentine's strike away from danger.

Adnan Januzaj had a half-chance down the other end moments later, but the Belgian fired wide of the post after a smart knockdown from Robin van Persie.

The Dutchman then met a cross from Di Maria after 15 minutes, but his header failed to test Hart, with United impressing in the early exchanges at Eastlands.

Aguero remained the main threat for the hosts, but De Gea was again equal to the striker's effort after 20 minutes, before the United stopper instinctively denied Jesus Navas from close range.

Moments later, De Gea was in inspired form once again to thwart Aguero, who had met a cross from Fernando, with a brave block.

City continued to grow into the first period, with Yaya Toure curling a free kick high of the crossbar as the match approached the 30-minute mark.

United were reduced to 10 men in the latter stages of the half when Smalling saw red, with Michael Carrick coming on for Januzaj to fill in at centre-back.