Ronaldo promised Real Madrid fans a special treat before Sunday's crucial game against Athletic Bilbao and the Brazilian striker remained true to his word as he scored twice in their 3-1 win to give Real a record 29th title.

After a week in which the imminent arrival of England captain David Beckham from Manchester United has overshadowed the team's league decider, Real got back to business to end Real Sociedad's league ambitions.

Sociedad started the day two points behind their rivals from the Spanish capital but, despite a 3-0 win over Atletico Madrid, they were frustrated in their bid to lift their first title in 21 years.

As the final whistle sounded at Real's Santiago Bernabeu stadium, Ronaldo and his superstar teammates celebrated under a spectacular fireworks display.

The World Cup winner had taken the field with a complete skinhead apart from a tuft of hair at the front - a style he sported in the closing stages of the World Cup finals last year as he led Brazil to victory.

Ronaldo, completing his first season with Real, opened the scoring after just nine minutes finishing off a move which started with Luis Figo darting down the left wing.

The Portuguese winger's pass found Roberto Carlos, who produced a defence-splitting pass from the touchline which left Ronaldo to slot home the ball home from close range.

Real had two other chances, from Raul and Ronaldo, with Athletic goalkeeper Daniel Aranzubia pulling off brave saves before former Spanish international Bitor Alkiza levelled the scores after 36 minutes with his first goal of the season.

Alkiza was given acres of space just outside the box and his swerving left foot shot from 20 metres left Real goalie Iker Casillas standing staring at the ball as it hit the net.

However, there were a few anxious minutes for the capacity 75,000 crowd packed into the Bernabeu.

Real took the lead again nearly two minutes into first-half injury time when Roberto Carlos fired home one of his trademark thunderbolt freekicks.

The game ended as a contest when Zinedine Zidane caught the Athletic defence napping just after the hour and Ronaldo ran through their poorly executed offside trap to score his 23rd league goal of the season.

Ronaldo's stellar season silenced his many critics who voiced their concerns when he arrived from Inter Milan last August about whether he would stand up to the week-in week-out punishment of the Spanish first division.

In the end, he had the second highest tally of goals in the Spanish first division behind the 29 notched up by Deportivo's Dutch striker Roy Makaay.

Real Sociedad looked as though their nerves had got the better of them during the first half of their encounter against Atletico, which ended goalless, but they hit top gear after the break.

Goals from Darko Kovacevic, Javier De Pedro and Nihat Kahveci gave them a comfortable victory, although it was ultimately in vain.

Athletic's loss at Real Madrid opened the door for Barcelona to move up to sixth and snatch the last UEFA Cup place.

The Catalans took full advantage of the opportunity and beat the Champions League-bound Celta Vigo 2-0 in the Nou Camp.

Juan Pablo Sorin opened the scoring after eight minutes and his fellow Argentine Javier Saviola added Barca's second early in the second half.

Both teams played most of the game with 10 men after Celta's Angel Lopez caught Frank de Boer in the face, with his elbow while both men were jumping for the ball midway through the first half, and was given his marching orders.

Patrick Kluivert also saw red after Barca's Dutch striker let his fragile temper get the better of him again and struck Angel in the melee that followed the foul.

Barcelona's UEFA Cup place will be modest compensation after a traumatic season.

At the halfway point, they were projected to finish in the bottom half of the Spanish first division for the first time for more than 50 years.