Spain's Athletic Bilbao stunned Manchester United with a convincing performance in the Europa League on Thursday, outclassing the English champions in a 3-2 away win in the first leg of the last 16.

Behind 1-0 to Wayne Rooney's 22nd-minute goal, Bilbao then ripped United apart with an attacking master class, Fernando Llorente equalized just before halftime before Oscar de Marcos and Iker Muniain scored in the final 18 minutes.

Rooney grabbed his second from the penalty spot in stoppage time, but Bilbao should have been well clear by then after spurning a series of great chances against the competition favorites in a dominant performance at Old Trafford.

The second leg will be played at Bilbao's San Mames stadium next Thursday.