Barcelona increased their lead at the top of the Spanish Primera Liga to a provisional seven points with a 4-1 win at Real Zaragoza on Saturday.
Champions Valencia's already faint hopes of retaining their crown faded even further, however, after a 2-1 home defeat by Deportivo Coruna that leaves them trailing Barca by 16 points.
Barcelona's victory, their first at La Romareda stadium since 1997, puts them well clear of second-placed rivals Real Madrid, who visit Osasuna on Sunday.
Zaragoza fell behind to an own goal by defender Delio Toledo in the second minute as he tried to fend off Ludovic Giuly, and the French international was on target himself after half an hour to increase Barcelona's lead.
Samuel Eto'o put the game beyond the home side when he found the net nine minutes later and although Luciano Galletti scored in the second half, Mexico international Rafael Marquez sealed the victory with a header in the 71st minute.
The game got off to a tense start, with thousands of seething fans waving red cards to protest against refereeing decisions they claim contributed to recent league defeats.
The home team recovered from the early own goal to put together an aggressive attacking game, outpacing a slow Barcelona side who made little headway outside their own half.
But Zaragoza's eagerness to find an equaliser left holes in their defence that Giuly was able to exploit when he outran a clutch of defenders to pick up a pass from Eto'o and knock the ball into the net.
The goal gave Barca a boost and they launched a string of attacks with league-leading scorer Eto'o notching his 17th of the season when he tipped the ball over Ruben as the keeper fell to his knees and ran round him to knock it home.
Barcelona's third goal seemed to break Zaragoza's spirit in what was left of the first half but the home side came out fighting after the break.
Just over an hour into the match Luciano Galletti threaded a pinpoint shot between two defenders past Barca keeper Victor Valdes and into the corner of the net.
But the visitors extinguished any hopes of a comeback in the 71st minute when a Marquez's header bounced in off the post after a corner from Xavi.
Deportivo went some way to wiping out the painful memory of a crushing 5-1 defeat at home to Valencia earlier this season as they cheered their fans with just their second win in 11 games.
Lionel Scaloni put the visitors ahead on the stroke of halftime after a shot at goal bounced off David Albelda and flew over keeper Andres Palop into the net.
The Valencia players headed for the dressing rooms to whistles from some fans but Italy striker Marco Di Vaio brought back the applause after the break when he knocked home a cross from Francisco Rufete to open up the game in the 51st minute.
Their hopes slipped away again after 73 minutes when a back-heel from Diego Tristan was picked up by midfielder Victor who outwitted Palop as he sent the ball across him into the net.
The defeat means Valencia have taken just three points from five games and has further upset their disgruntled fans, many of whom left their seats before the final whistle.