Barcelona coach Pep Guardiola has warned his side against complacency in the Primera Division title race.
Guardiola is wary despite seeing Barca take what could be a decisive step towards winning La Liga this weekend.
After Real Madrid suffered a shock home defeat to Sporting Gijon earlier in the evening, Barca extended their lead at the summit to eight points with only eight games remaining by beating Villarreal 1-0.
Madrid coach Jose Mourinho said after his side's loss that it would be "practically impossible" for them to win the title if Barca picked up three points at El Madrigal, and the Catalan giants now look set for a third successive title.
However, Guardiola said: "If with an eight-point advantage with eight games to go you see yourselves as champions, you can only lose the league.
"In the end leagues are won when they are won. There are some terribly tough games to come.
"We have gained the biggest advantage of the season and it's very good, but in sport anything can happen. Madrid are always going to fight until the end. Although it is better to be eight points ahead than five."
Barca defender Gerard Pique, who scored the winner against Villarreal, added: "We have taken a very important step, but there are eight weeks left and that's a lot of points. This isn't decided."
Guardiola was also asked about his interview with Italian television channel Rai Sport that was made public on Friday, in which he was quoted as saying: "I think my time is ending here in Barcelona."
Speaking after the Villarreal match, Guardiola said: "They are statements that you already know, I've not said anything new.
"I didn't say that I'm going to leave, but that I'm closer to the end.
"When you've spent three or four years as coach of a team you are always more closer to the end of your career than continuing. This isn't something that I've just said in Italy, but that I've said on other occasions."
