Ronald Koeman promised Barcelona would "go with everything we have" to secure the LaLiga title on an evening when Atletico Madrid faltered again. (More Football News)
The trophy, and a domestic double, looked unlikely prospects as Barcelona stumbled through the opening months of the season.
Yet they will head into May with the Copa del Rey locked away in the trophy room and league glory could follow.
Long-time leaders Atletico have struggled without former Barcelona frontman Luis Suarez recently, and although he came off the bench in Sunday's clash with Athletic Bilbao, Diego Simeone's wobbling side suffered a 2-1 defeat.
It means that although Atletico still hold a two-point lead at the top, Barcelona and Real Madrid are the closest chasing sides, level on 71 points. Importantly, Barca have a game in hand over both their rivals.
The Camp Nou club's 2-1 win over Villarreal strengthened their championship case, with Real Madrid only able to draw 0-0 with Real Betis on Saturday.
Asked about the prospect of a league and cup double, Koeman said on Sunday: "I have never said that it is impossible, but when you have a distance of points and you are behind, you have to go game by game.
"We're in there. But the best way to win this league is to go game by game."
Speaking after Barcelona's win but before Atletico fell to their jolting defeat, Koeman praised his side, who have now gathered 46 points from a possible 51 since the turn of the year in LaLiga.
Of their last 24 clashes with Villarreal in LaLiga, Barca have won 18 times and drawn the other six, a staggeringly good record against one of Spain's better club sides.
"It is closer, but I don't know if it is very close," Koeman said of the title. "We have a track record of many victories. And what the team are doing is something very big, trying to win LaLiga as well.
"We know that if we win all six games we will be champions. We are going to go with everything we have to try to win LaLiga."
Atletico have lost two of their last five LaLiga games, showing fallibility at just the wrong time. They had previously lost just two of 44 league matches, including a strong finish to last season.
A Camp Nou clash between Atletico and Barcelona on May 8 is the standout fixture of the title run-in, and momentum can quickly turn.
Before that, Barca have games against Granada on Thursday and at Valencia on Sunday.
Koeman said it is "difficult to be 100 per cent" when games are coming so thick and fast.
But having come so far, making up so much ground when at one point qualifying for the Champions League looked to be in doubt, Barcelona are determined not to slow down.
As goalkeeper Marc-Andre ter Stegen put it on Instagram: "6 finals to go. We must be ready for Thursday."
