Real Madrid players had been saying all week that they had to beat Valencia to stay in the Spanish title race and they did just that with a 2-1 victory over the 2002 and 2004 champions on Saturday.
Goals from Ruud Van Nistelrooy and Sergio Ramos means that Real move up to second place, at least overnight.
The 29-time Spanish champions are now two points ahead of Sevilla but still two points behind the league leaders and their eternal foes Barcelona with seven games to go.
Both of Real's two main rivals for the La Liga crown also have a game in hand and play Sunday.
Van Nistelrooy scored his 17th league goal of the season with a spectacular right-foot volley from just inside the right hand edge of the area after an inch-perfect pass from Miguel Torres on the left wing.
Real then had a purple patch of around 15 minutes when Van Nistelrooy and club captain Raul Gonzalez should have added to their tally.
However Valencia got back into the game just before the break and shortly afterwards Fernando Morientes scored against his old club, where he had spent eight seasons and been part of teams that had won the Champions League three times.
Morientes found the net seven minutes after the break after finding the space to side foot home a Joaquin Sanchez cross, after the Spanish international winger had outsprinted Torres down the right wing.
Real were clearly determined to maintain their championship challenge against a team that had beaten them in the Santiago Bernabeu last season.
Sergio Ramos got the winner 17 minutes from time when he rose above the Valencia defence to head home a David Beckham free kick.
It was a huge contribution from the former England captain after only being on the pitch barely five minutes and was playing his first game for six weeks after recovered from a knee injury.
Real were overall the better side but still had to survive some nervous moments in the final as Valencia pressed hard for a draw.
Once again, Real's hero on the night was not just the men who found the net but their goalkeeper Iker Casillas, who made an outstanding diving save to deny his fellow Spanish internationals Aitor Del Horno and David Villa in the final minutes.
Barcelona are aware that lifting their third successive Spanish title is in their own hands as they aim to maintain their advantage at Villarreal on Sunday.
Barca coach Frank Rijkaard named two-time World Player of the Year Ronaldinho in his squad after the Brazilian missed the reigning champions' last two games due to a bout of tonsillitis.
"He (Ronaldinho) is feeling a lot better and has recovered his energy. I would not have included him if he was still feeling tired or ill. He wants to participate," said the Dutch coach at a press conference on Saturday.
Sevilla are in second, four points behind the reigning champions, and will face relegation-threatened Athletic Bilbao on Sunday.
Athletic's near-neighbours Real Sociedad continued to keep alive their won hopes of avoiding relegation with their third win in four games, beating Atletico Madrid 2-0 on Saturday.
The San Sebastian side took an early lead with Darko Kovacevic stabbing the ball home from the edge of the six yard box, following a cross from the left wing by Savio, after seven minutes.
Atletico's chances of salvaging a point started to diminish severely with 20 minutes to go.
Firstly, their French midfielder Peter Luccin was sent off for trying to con the referee about an inexistant foul and 10 minutes later go when Brazilian defender Fabiano Eller picked up his second yellow card.
Savio then secured three points for Sociedad with six minutes remaining, scoring with his left foot from almost exactly on the penalty spot.