LONDON (AP) -- The two Manchester clubs are facing a battle to stay in the Europa League after slumping to surprise losses in the first legs of their last-16 matches on Thursday.
United was outclassed at home by Spanish side Athletic Bilbao, losing 3-2 after going ahead through the first of Wayne Rooney's two goals.
Fernando Llorente, Oscar de Marcos and Iker Muniain were the scorers for Bilbao, which could have won by a bigger margin at Old Trafford.
City lost 1-0 at Sporting Lisbon thanks to an impudent back-heeled goal by Brazilian defender Xandao, but at least have the return leg at home to come next Thursday.
It was a successful night for Spanish clubs, with Valencia beating PSV Eindhoven 4-2 and Atletico Madrid winning 3-1 against Besiktas.