Madrid, Jan 28 (IANS): FC Barcelona and Celta Vigo booked their places in the semi finals of the Spanish King's Cup on a dramatic Wednesday night.

Although Barca were favourites to qualify after winning the first leg of their tie 2-1 away to Athletic Club Bilbao a week ago, they were made to suffer as the Basques gave a heroic performance in the Camp Nou Stadium and leveled the tie through Inaki Williams goal after 12 minutes.

Athletic outplayed Barca as no other side has done this season in the first 45 minutes but Barca leveled on the night when Luis Suarez scored following an unfortunate slip by visiting defender Mikel Balenziaga early in the second half, reports Xinhua.

The tie was in the balance until 10 minutes from time when Gerard Pique scored Barca's second after Dani Alves had been allowed to get away with a foul in attack before crossing for the defender to score. Neymar sealed the win in injury time.

Celta Vigo produced the surprise of the night as they knocked Atletico Madrid out of the tournament with a 3-2 win in the Vicente Calderon Stadium.

Atletico were clear favourites after their 0-0 in Vigo a week ago, but Pablo Hernandez's goal in the 22nd minute left them needing two to qualify for the last four.

Antoine Griezmann scored for Atletico in the 29th minute, but goals from Jon Guidetti and a second from Hernandez for Celta left them needing three goals in the last half hour to qualify and although Angel Correa gave them hope with 10 minutes to go, Celta held on with few problems to reach the semis.