Ronaldinho struck twice as he steered Barcelona to a flattering 3-0 home win over Recreativo Huelva on Saturday, while arch-rivals Real Madrid were also rather fortunate to come from behind to beat Gimnastic 3-1 away.
Valencia slipped to their second defeat of the season when they lost 1-0 in the fog at Racing Santander and finished with 10 men as midfielder Mario Regueiro was sent off for picking up two yellow cards.
The results mean Barcelona remain top with 19 points from eight games with Real now in second place two points adrift of the champions and one ahead of Valencia.
Barca coach Frank Rijkaard has raised concerns about their lack of concentration after losses to Chelsea and Real and they almost conceded a goal in the opening minute against Recre.
Visiting striker Calle beat Carles Puyol to a cross and it took a brilliant one-handed reflex save from Barca goalkeeper Victor Valdes to keep the ball out.
The home side lacked fluency and looked shaky at the back but were gifted the lead from the penalty spot after Eidur Gudjohnsen went to ground when former Barca defender Mario touched his shirt.
Ronaldinho blasted his kick high into the net to put the Catalans in front although Barcelona did little else to deserve their halftime lead.
The Brazilian sparked his team into life after 57 minutes, though, putting them 2-0 up with a rare headed goal after a great cross from left back Silvinho.
The other players lifted their game in response and three minutes later Xavi added another with a mirror-image
This time Juliano Belletti provided the cross from the right and the midfielder finished it off.
Real were overrun by a lively Gimnastic in the opening minutes at the Nou Estadi and struggled to contain their opponents' rapid counter-attacks.
The home side took a deserved lead in the 28th minute when midfielder Abel Buades scored from the penalty spot after Fabio Cannavaro brought down Ariza Makukula as he raced into the area to meet a pass from lively winger Gilberto.
But Real equalised on the stroke of halftime when Roberto Carlos drilled a powerful shot under the wall after a free kick on the edge of the area.
Another defender Ivan Helguera put them 2-1 up four minutes after the break, powering home a header after being left unmarked at a corner.
Real ended the game on a high as the in-form Robinho added a third when he met a Sergio Ramos cross with a clever volley after a fine passing move involving Raul and Mahamadou Diarra four minutes from time.
Racing's little and large partnership of Pedro Munitis and Nikola Zigic provided one of the few bright points of a gloomy game against Valencia when they manufactured the winner.
Munitis looped a header over keeper Santiago Canizares after giant Serbia striker Zigic nodded on a lofted pass into the area 11 minutes after the break.