Barcelona and Atletico Madrid knew victory could fire them towards the La Liga title but Saturday's 0-0 draw at Camp Nou instead handed Real Madrid the chance to take pole position.
Four wins from their last four games will now be enough for Zinedine Zidane's side to retain their La Liga crown, with a crunch game at home to fourth-placed Sevilla up first on Sunday.
The first part of a blockbuster weekend in the Spanish title race pitched first against third but neither could take a decisive step forward, despite the best attempts of Lionel Messi and Luis Suarez, who faced each other for the first time since Suarez departed last summer.
A point each leaves Atletico three points clear of Real Madrid, who have a game in hand and also the superior head-to-head over both Atleti and Barcelona.
Barca remain two points off the top but their chances took the biggest hit, given they now need both Atletico and Real Madrid to slip up in the final stretch.
Anything can still happen because of what we've seen so far," said Gerard Pique. "If Madrid wins their four games they will be champions, but it is difficult for the big teams to be consistent. If we win all our three games, I think we'll have a chance."
Atletico will be disappointed too, given they spurned a number of chances in during a dominant first half, before Ronald Koeman's side recovered in the second.
Jan Oblak had to deny Messi after a vintage run forward from the Argentine, who then had a well-placed free-kick in the last minute, only for Atletico to watch the ball spin inches wide.
"We started better and they finished a little better," Oblak said. "Real Madrid has four games left but for sure they are going to be tought games. We have to keep going."
Formner Barca favourite Suarez was not at his ruthless best as a handful of openings went unconverted in a contest full of chances but that lacked precision when it mattered most.
Atletico slowly took charge of the game, helped by the departure of Sergio Busquets, who was replaced by Ilaix Moriba after a clash of heads that he was taken to hospital for tests.
Without Busquets, Barcelona were rudderless for a while and the Atletico chances came thick and fast.
Marc-Andre ter Stegen had to palm away Marcos Llorente's shot and then stuck out a foot to deny Suarez.
The Uruguayan striker then tried to nod in the rebound after a winding run from Yannick Carrasco before claiming a penalty after feeling a flick of Ter Stegen's hand across his head.
Barcelona were rattled, the usually steady Ter Stegen booting one ball straight into the stands, only for Messi to give Atletico a reality check, his driving run past six chasers opening the space for a shot, but Oblak tipped it wide.
Felipe fired over from a well-worked Atleti short corner before half-time but Barca were better after the break, with both Ilaix and Pique going close shortly after the hour.
Both managers made changes, hoping to inspire a winner. Ousmane Dembele was one of them and he should have grabbed it with six minutes left but headed over from six yards in perhaps the best chance of the game.
Messi could have won it at the end, standing over the ball with a free-kick placed centrally and 25 yards out. Atletico held their breath, the ball whistling just wide of Oblak's post.
