Real Madrid had to settle for a 0-0 draw at Valencia in the Spanish Primera Liga on Saturday after substitute Ronaldo spurned a golden opportunity to give his side victory when he missed a last-minute penalty.
The Brazilian, who was dropped to the bench by Real coach Juan Ramon Lopez Caro, earned the spot-kick after he was fouled by Santiago Canizares but the Valencia goalkeeper atoned for his error when he saved Ronaldo's low shot.
"Things aren't going well at the moment but I can only get out of this situation with enthusiasm and hard work," the striker told reporters after the game.
The draw played into the hands of leaders Barcelona, who have an opportunity to extend their nine-point lead at the top when they travel to fourth-placed Osasuna on Sunday.
Barca top the table on 61 points, Valencia and Real have 52 and Osasuna are six further back with 46.
Earlier, Celta Vigo missed their chance to move into the Champions League places when they lost 2-0 at 10-man Espanyol.
The defeat meant the Galicians, who had won four of their last five games, remain fifth a point behind Osasuna.
Real Sociedad eased their relegation worries by taking their first points in five games with a 1-0 win at Deportivo Coruna, whose last victory at the Riazor was three months ago.
Sociedad are now five points clear of the relegation zone, although their immediate rivals have yet to play this weekend.
RONALDO ON BENCH
Real coach Lopez Caro made the surprise decision to leave Ronaldo on the bench after his failure to find the net as Real slipped out of the Champions League in the first knockout round on Wednesday following a goalless draw at Arsenal.
He also left out forwards Antonio Cassano and Robinho, choosing instead to play Raul and Julio Baptista up front.
But the changes failed to add more spark to the Real attack and scoring chances were scarce in the first half as the sides battled hard in midfield and got plenty of men behind the ball.
The first clear opportunity did not come until just before the break when Valencia striker David Villa had a goal-bound free kick tipped over the bar by Iker Casillas.
Valencia continued their pressing game in midfield in the second half and although Real had more possession they had problems getting near the opposition area.
Lopez Caro sent Ronaldo on in place of Raul just after the hour, although it was his strike partner Baptista who almost opened the scoring a few minutes later.
The Brazilian looked certain to find the net when he got his head to a Zinedine Zidane cross but Canizares produced a great reflex save to scoop the ball off the line.
Cassano and Robinho added new life to the Real front line when they too were thrown into the mix in the final 15 minutes.
The Italian had a hand in winning the penalty when he exchanged a neat one-two with Ronaldo a minute from time.
The Brazilian was felled by Canizares as he burst towards goal but was then denied his 11th goal of the season when the Valencia keeper went the right way to save his spot kick.
