Barcelona were inspired by Ronaldinho as they returned to the
top of La Liga, while Ruud van Nistelrooy scored four goals as
rivals Real Madrid also won.
Barca came from 1-0 down to beat Real Zaragoza 3-1 but forward
Lionel Messi limped off and faces up to three months out with a
broken bone in his foot.
The win moved the Nou Camp outfit a point ahead of second-placed
Sevilla, with Real Madrid three behind Barca.
Real beat Osasuna 4-1, with David Beckham coming on in the 83rd
minute.
But the game was already realistically over at 3-1 when Beckham was
introduced as a substitute, with former Manchester United striker
Van Nistelrooy showing his lethal streak in front of goal.
The Dutchman opened the scoring after 12 minutes when he slotted in
a rebound after Robinho's shot had been blocked.
His second goal came after an attempted clearance hit Robinho and
fell into his path and he completed a first-half hat-trick with a
precise 18-yard, left-foot strike.
Valdo Lopes pulled one back for Osasuna but Van Nistelrooy took his
La Liga tally to eight for the season when he was set up by Emerson
late on.
Van Nistelrooy's exploits upstaged Ronaldinho, even though the
Brazilian grabbed a brace for Barca after Real Zaragoza had taken a
shock lead.
Ronaldinho equalised with a header before Thiago Motta was sent off
for brushing off Diego Milito with his arm - his dismissal sparking
lengthy protests from the Barcelona players and coach Frank
Rijkaard.
Zaragoza were also down to 10 men shortly afterwards when Gabriel
Milito was red-carded for holding Javier Saviola.
Barcelona were kept at 1-1 until the 86th minute when Ronaldinho
scored with an angled 20-yard free-kick, while Saviola added a
third in injury time.
Argentine teenager Messi only lasted 23 minutes of the ganme before
being forced off.
"Messi has fractured the fifth metatarsal in his left foot," said a
medical statement on the Barcelona website.
"The treatment will be surgical and the expected loss is around
three months."