The Reds beat the Basque side courtesy of a second-minute own goal and forged numerous chances afterwards to put the game to bed.
Japanese midfielder Shinji Kagawa was at the heart of many of United's best moves and missed a golden chance himself to add to the scoreline. Fans on ManUtd.com and the club's Twitter account voted him Man of the Match after the final whistle.
Making just his fourth start this season, Kagawa certainly made a strong case for retaining his spot in the side for Saturday's Barclays Premier League encounter against Stoke.
"I thought it was Shinji's best game in my time here," Moyes said.
"He hadn't really found his feet yet but I saw something from Shinji tonight which I hadn't seen in other games, so I was really pleased."
"His effort when we didn't have the ball was fantastic. With Shinji, everybody tells me about his ability and what he has got, but tonight is the first time I’ve really seen Shinji.
"I thought when we put him into the no.10 role, and even after it, he was good with Wayne. His attitude and energy were excellent and I was pleased for him."
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