Both teams have 73 points but Real remain on top due to better head-to-head record in their meetings this season.

A victory for Real at home to Real Mallorca next week will secure them their 30th La Liga title. Barcelona travel to already-relegated bottom club Gimnastic Tarragona but have to hope that Real slip up.

The man who Real have to thank for keeping them in pole position is Ruud van Nistelrooy, who got both their goals and whose left foot shot just a minute from the end secured them possibly their most vital point of the season.

Zaragoza took the lead through a Diego Milito penalty after 32 minutes following a foul by Ivan Helguera on Pablo Aimar.

Former Real Madrid goalkeeper Cesar Sanchez then produced a brilliant save to deny Ruud van Nistelrooy an equaliser in the dying seconds of the first half but could do nothing to stop the Dutchman's header from a Sergio Ramos pass after 58 minutes. Milito then put Zaragoza back in front six minutes later when he danced through the Madrid defence before unleashing a left foot shot that gave Real goalkeeper Iker Casillas little chance.

However, Real refused to give up and, with the title at stake, showed the fighting spirit that has brought them back into contention over the second half the season.

Van Nistelrooy's last gasp effort takes his tally to 26 league goals for the season and gives him at least a half-share of the European Golden Boot award with Roma's Francesco Totti.

Barcelona's Lionel Messi has often been called The New Maradona and he emulated his hero and compatriot with a goal similar to the Argentine striker's famous Hand of God effort against England in the 1986 World Cup.

Barca's Italian international Gianluca Zambrotta lofted a pass into the area and Messi lifted up his left arm to nudge the ball into the net just before half time.

Espanyol, who had taken the lead against the run of play thanks to Raul Tamudo after 30 minutes, protested long and hard but to no avail and referee Julian Rodriguez Santiago let the highly dubious goal stand.

His second goal was far less controversial, with him being left unmarked and having the space to run on to a Deco pass on the right side of the box before slotting the ball home after 58 minutes.

However, a lapse of concentration could have cost them the title leaving Tamudo to get an equaliser just 25 seconds before the end of regulation time.

Sevilla stay in third and still have an interest in the title race after their 0-0 draw at Real Mallorca but are two points behind the leading pair.

The UEFA Cup winners were sorely missing their injured strikers Fredi Kanoute and Alexsander Kherhakov and had to survive the last 10 minutes with one man less after defender Ivica Dragutinovic got two yellow cards in less than a minute.

At the other end of the table, four clubs are still involved in the relegation battle.

Athletic Bilbao went down 3-1 at Villarreal while Real Betis crashed 5-0 at home to Osasuna to keep them both just one point above the relegation zone.

Celta Vigo pulled off a surprising 3-2 win at Atletico Madrid to keep their hopes alive although they stay third from bottom.

Maxi Rodriguez hammered home a Fernando Torres from the edge of the area after 28 minutes to put Atletico ahead but barely a minute later Fernando Baiano had equalised for Celta from the penalty spot.

Yago Alonso-Fueyo headed Celta ahead from a corner three minutes after the break and Baiano put the visitors further ahead before Maxi reduced the deficit for Atletico.

Real Sociedad could only draw 0-0 at home to Racing Santander and slip to second from bottom, three points away of securing their survival which can now only happen with an unusual combination of results on the final weekend.