Real Madrid put a week of turmoil behind them after Florentino Perez's shock resignation as president with a gutsy and determined performance to earn a 2-1 win over city rivals Atletico Madrid on Saturday.
But although the victory moved Real up to second place it did little to further their title hopes as champions Barcelona extended their lead at the top to 10 points with an exhilarating 3-2 win at home to Deportivo Coruna in the day's late match.
Barca have 61 points from 26 matches ahead of Real on 51 and third-placed Valencia who are a further point behind but can reclaim second spot with a win at bottom club Malaga on Sunday.
Barca got off to a perfect start against Depor when World Player of the Year Ronaldinho sent an unstoppable free kick over the wall and dipping into the top corner in the third minute.
A gritty Depor equalised when defender Juanma powered home a header after outjumping the Barca centre-backs at a corner in the 15th minute at the Nou Camp.
The home defence was found wanting again when Portuguese defender Jorge Andrade stole a march on them to squeeze a header inside the post after Pedro Munitis clipped a free kick into the area just before the half-hour mark.
Sweden striker Henrik Larsson began the Barca fightback when he threw himself at a Ronaldinho corner to make it 2-2 with a great diving header after 34 minutes.
Samuel Eto'o clinched the win with his 19th goal this season when he prodded the ball over the line after a Ronaldinho corner bobbled across the goal line 16 minutes into the second half.
New Real president Fernando Martin's hard-line declarations after taking over from Perez seemed to have an immediate effect as the players flew out of the blocks at the Bernabeu and took the lead with a little over four minutes on the clock.
Italy striker Cassano, starting a league match for the first time since joining Real in January, headed home unopposed at the far post after Roberto Carlos charged down the left wing and whipped a perfect cross into the area.
However, the goal did not stop Real's ultra fans unfurling a banner in the 15th minute bearing the phrase "Florentino, you aren't to blame. Mercenaries out of this great club."
With Brazil striker Ronaldo watching from the stands after being dropped from the Real squad this week, Cassano appeared determined to take his chance and his lively running was a constant menace to the Atletico defence.
But just as Real looked to be taking control, Atletico hit back with a clever finish from Mateja Kezman who wrong-footed home keeper Iker Casillas when he back-heeled a Peter Luccin drive into the net after a corner just before the half hour.
Kezman then had a great chance to put Atletico ahead but lashed the ball over the bar with the goal at his mercy and moments later Real restored their lead after a marvellously worked counter-attack five minutes before halftime.
Zinedine Zidane found David Beckham on the right and the England captain rode one challenge before whipping the ball towards the near post where Baptista poked home.
Atletico had the better of the second half and pinned Real in their own area for the last quarter, but without influential playmaker Ariel Ibagaza and in-form forward Maxi Rodriguez were unable to put the finishing touch to some promising attacks.
Real skipper Raul, who has recently returned from a three-month injury layoff, replaced Cassano late in the second period to make his 400th Primera Liga appearance.
Earlier, Argentine playmaker Juan Roman Riquelme gave an inspired performance with two goals to lead Villarreal to a 3-2 comeback win at home to struggling Alaves that set them up nicely for next week's Champions League match against Rangers.