MADRID, Feb 16 (Reuters) - Real Madrid slipped to their second defeat in three games after surrendering an early lead to lose 2-1 at struggling Real Betis on Saturday.
And title rivals Barcelona closed the gap to just five points after a debatable penalty helped them beat Real Zaragoza 2-1.
Juanfran was harshly adjudged to have handled in the area but the ball seemed to conme off his shoulder.
Ronaldinho netted the spot kick with just six minutes of the game remaining.
Real Madrid Midfielder Royston Drenthe put the Primera Liga pacesetters in front in the sixth minute but Betis struck two quickfire goals before the break, Brazilian forward Edu heading the first and winger Mark Gonzalez nodding the second.
Improving Sevilla moved up to sixth with a 4-2 victory in an entertaining match at Espanyol.
Brazil striker Luis Fabiano took his tally for the season to 17 when he fired Sevilla's opening goal while African Footballer of the Year Frederic Kanoute added the second.
Christian Poulsen and Diego Capel were also on target for the visitors.
Espanyol, who had Pablo Zabaleta sent off after 65 minutes, have lost five out of six games but remain fifth, three points clear of Sevilla.
Real Madrid got off to the perfect start at the Ruiz de Lopera when Drenthe angled a shot in at the far post after fellow Dutchman Arjen Robben cut the ball across the area.
The visitors had two good chances to extend their advantage as Raul fired straight at Portugal keeper Ricardo and Robben lashed over with his weaker right foot.
Just as Madrid looked to be at their most comfortable, Betis hit back with two goals in four minutes.
Edu got in between Madrid defenders Marcelo and Sergio Ramos to power in a header at the far post from a cross by Mariano Pavone.
The second was an almost exact replica, except this time it was former Liverpool winger Gonzalez who outjumped Ramos and Marcelo to head in after Edu had turned fullback Michel Salgado inside out before crossing.
Madrid coach Bernd Schuster planned to rest Ruud van Nistelrooy before Tuesday's Champions League match against AS Roma but threw on the striker with half an hour to go.
The Dutchman almost equalised when he hit the post before Betis went on to claim their first points in three games to move four points clear of the drop zone.
Barcelona were fortunate to beat Zaragoza at the Estadio La Romareda.
Barca took the lead at Real Zaragoza when Thierry Henry received a lovely chipped Deco pass and struck past César in the 34th minute.
Eight minutes later the home side had a glorious chance to equalise when Rafael Márquez was harshly adjudged to have brought down Ricardo Oliveira in the penalty area.
Replays suggested Oliveira had made the most of, at best, minimal contact.
However, Diego Milito blasted his spot kick well over the crossbar.
Zaragoza did pull level early into the second period when Ricardo Oliveira made the most of a swift break from Sergio Garcia and struck from close range.
But a controversial penalty award - for handball against Juanfran gifted Ronaldinho the chance to win the game for Barca, which he duly did with a precise finish.