Record signing Philippe Coutinho came off the bench to score his first goal for Barcelona as they reached the Copa del Rey final with a 2-0 win at Valencia, progressing 3-0 on aggregate.
Coutinho was brought off the bench at half-time for his fifth appearance since his ВЈ142 million switch from Liverpool last month and scored four minutes after the restart, sending the ball into the corner of the net having slid to meet Luis Suarez's cross.
Ivan Rakitic, also teed up by Suarez, then added the visitors' second in the 82nd minute to secure progress to a showdown against Sevilla in what will be defending champions Barcelona's fifth consecutive Copa del Rey final.
Lionel Messi -- restored to the side having only made a substitute appearance in the 1-1 La Liga draw at Espanyol on Sunday -- saw an early free kick saved by Jaume.
Barcelona then had a scare as Rodrigo headed against their bar around the quarter-hour mark. Valencia threatened again in the 28th minute when Rodrigo's shot was saved by Jasper Cillessen.
Messi hit an effort just wide, and the closing stages of the first half saw Suarez miscue a shot inside the box, allowing Domenech to gather, before Valencia's Geoffrey Kondogbia sent a shot into the side-netting having combined with Daniel Parejo.
Barcelona changed things at the interval by bringing on Coutinho for Andre Gomes, and the Brazilian made a near-instant impact as he got his right leg to Suarez's cross from the left to send the ball across Domenech and in.
Suarez then curled an effort wide before Valencia substitute Carlos Soler went close at the other end, shooting the wrong side of the post.
Barcelona were soon back on the front foot and Messi's shot was parried by Domenech, with Gabriel and Ezequiel Garay then thwarting Messi and Rakitic.
Coutinho tried his luck from outside the box, with Domenech making the catch, and Cillessen pulled off a superb save to deny Jose Luis Gaya.
Rakitic then confirmed it would not be Valencia's day as he lashed in having received the ball from Suarez, who had claimed possession by seizing on a misplaced Gabriel pass.
Substitute Enes Unal scored twice in the final nine minutes as Villarreal dealt a major blow to Atletico Madrid's hopes of catching Barcelona at the top of La Liga with a 2-1 victory.
Cristiano Ronaldo scored his 50th career hat trick, then went on to add a fourth goal as Real Madrid beat Girona 6-3 in La Liga on Sunday.
Lionel Messi scored for the sixth consecutive game in all competitions as Barcelona tightened their grip in the title race with a 2-0 La Liga win over Athletic Bilbao.
Simone Zaza scored one goal and set up another for Rodrigo Moreno as Valencia claimed a 3-1 La Liga win over Alaves at the Mestalla Stadium.
Atletico Madrid returned to winning ways in style by easing past Celta Vigo in a 3-0 win to reduce the gap to league leaders Barcelona to eight points.
Barcelona tightened their grip at the top of La Liga with a 2-0 win at bottom club Malaga, who played for an hour with 10 men.
Real Madrid overcame a shaky performance to maintain their fine recent form to defeat Eibar 2-1 at the Estadio Municipal de Ipurua.
Lionel Messi's 600th career goal sank Atletico Madrid 1-0 and ensured Barcelona stretched their lead at the top of La Liga to eight points.
Cristiano Ronaldo scored his 300th LaLiga goal as Real Madrid returned to winning ways with a 3-1 victory over 10-man Getafe at the Santiago Bernabeu.