Xavi Hernandez said LaLiga is Barcelona's to lose after they beat Real Madrid 2-1 at Camp Nou on Sunday to move 12 points clear at the top of the table.
Franck Kessie came off the bench to score a stoppage-time winner for Barca after Madrid's Marco Asensio had seen a late goal ruled out by VAR for offside on a dramatic day in the title race.
- Stream on ESPN+: LaLiga, Bundesliga, more (U.S.)
- Marsden: Barcelona's Clasico win sure to decide LaLiga
With just 12 games left to play, Barca now find themselves in a commanding position as they chase a first league title since 2019, although Xavi insists they cannot relax.
"It's not definitive, I don't feel like we are champions yet, but it's a huge step forward," Xavi said in a news conference after the game.
"I am happy because [the lead is] 12 points with 12 games left, but it's not over. Only we can lose LaLiga, so we cannot switch off. We cannot relax. There are still a lot of games to go."
Barca have now won three matches in a row against Madrid in all competitions, something they had not achieved since 2011-12 when Pep Guardiola, who attended Sunday's game, was in charge.
It represents a remarkable turnaround since Xavi took over 18 months ago. Barca were ninth in the league at the time but eventually finished second and are well-placed to go one better this season.
"I don't think enough value is given to what the players are doing," Xavi added. "We have only dropped 10 points in LaLiga. I don't think that is spoken about enough. They have been extraordinary.
"Look at where we are coming from. Last season, we [finished 13] points behind. We were even three behind when we lost the Clasico [this season] in October -- that's a 15-point swing since then."
A Ronald Araujo own goal had given LaLiga holders Madrid an early lead as they sought to cut the gap on Barca to six points, but Sergi Roberto drew the home side level on the stroke of halftime.
Kessie's winner arrived in the second minute of added-on time -- minutes after Madrid thought Asensio had won them the game -- and Xavi felt his team deserved the three points.
"We had chances and the control of the game," he said. "In general, we were superior to Madrid. I think the key was minimising how often we gave the ball away. We didn't let them counter.
"We were responsible with the ball and dominated many phases of the match. In the last game [a 1-0 win in the Copa del Rey two weeks ago], they dominated us, but not today. We were better."
The Barca coach also said he was "surprised" by Madrid coach Carlo Ancelotti's complaints about Asensio's offside goal.
"It's a clear [decision]," he said. "Either it's offside or it isn't, there is no possible debate there."
The call to rule out Asensio's effort set the stage for Kessie's late strike, which featured a brilliant Robert Lewandowski back heel in the buildup and left Xavi with goosebumps.
"It's been one of the best days I have had [as Barca coach]," he said. "The fans deserved it. I remember when we lost 3-0 to Bayern Munich [in November]; they were here until the end, singing. I had goosebumps tonight when Franck scored -- and he deserved that. It's a day to be enjoyed."
Barca and Madrid now both break for international fixtures, but they will meet again at Camp Nou on April 5 in the Copa del Rey semifinal. The Blaugrana have a 1-0 lead from the first leg, with the winners meeting either Athletic Club or Osasuna in May's final.