An early Wayne Rooney strike proved the difference, and although the Reds dominated for long periods, the visitors also enjoyed spells of sustained pressure as they pursued an equaliser, ultimately in vain.
“In the FA Cup anything can happen. We’re relieved to be in the next round,” Giggs told MUTV.
“We got off to a great start but then we didn’t capitalise on that. We were a little bit sloppy in the last third. West Ham made it difficult for us. We should have built on that early goal. But credit to West Ham – they’re a tough team to play against.
“You’re always concerned when it’s only 1-0, no matter who you’re playing. But especially against West Ham – they can cause you problems from set pieces and when they put the ball into the box. We [ideally] needed to get that second goal, but luckily we hung on.”
The Reds’ best opportunity to put the game beyond doubt fell to Rooney, but the striker fluffed his 79th-minute penalty kick, sending it sailing over the bar. Giggs conceded his colleague will have been disappointed with his failure to find the net.
“Wayne, under pressure, has scored so many crucial penalties for us,” he said. “It’s not so bad when it doesn’t alter the result, but Wayne will be disappointed because he wants to score goals.”