Lionel Messi extended his Spanish league record by scoring in 17 straight games to cap Barcelona's 2-0 win over last-place Deportivo La Coruna on Saturday.
Messi started on the Camp Nou bench with several other first-choice players, saved for the decisive Champions League last-16 match against AC Milan, but went on in the second half and scored two minutes from time with a delicate chip shot to double Barcelona's lead after Alexis Sanchez opened in the 38th.
It was the four-time world player of the year's league-leading 40th goal of the season and 51st overall.
Barcelona hosts Milan on Tuesday, facing the daunting challenge of overturning a 2-0 loss in their first meeting to keep alive its bid for a fourth European title in eight seasons.
"Every competition is distinct, and Tuesday will be an entirely different story," said Barcelona assistant coach Jordi Roura. "But there is no doubt that the best way to get ready for a match is having won the previous game."
Barcelona's 12th win in 13 league home games provisionally extended its league lead to 14 points over Atletico Madrid.
"We have the league title in our hands and we are not going to let it slip away," Alexis said.
Meanwhile, Cristiano Ronaldo ensured there was no letdown for Real Madrid after its win over Manchester United by scoring twice in a 2-1 victory at Celta Vigo on Sunday, lifting the team into second place in the Spanish league.
Madrid slipped one point ahead of Atletico Madrid in the standings after high-flying Real Sociedad ruined Atletico's perfect home record this season after 13 league games with a 1-0 win thanks to forward Xabi Prieto's second-half goal.
Except for Celta's initial and last-gasp surges, Madrid had the better of the scoring chances at Balaidos Stadium despite manager Jose Mourinho making several changes to his starting team following a week featuring wins over Barcelona and United.
Ronaldo was well positioned to score from a loose ball in the 61st minute. Striker Iago Aspas leveled against the run of play two minutes later, but the Portugal forward converted a spot kick earned by Kaka in the 72nd for the winner.
Celta substitute Park Chu-Young almost grabbed the draw when his header hit the bar one minute from time, but Madrid hung on for its sixth straight victory in all competitions.
Ronaldo has 26 league goals this season, second only to Barcelona forward Lionel Messi with 40.
Madrid trails Barcelona by 13 points and has written off its title defense.
Malaga's winless run reached four consecutive games with a 1-1 draw at Valladolid as it continues to sputter before its Champions League match against FC Porto on Wednesday when it must come back from a 1-0 loss.
Messi on Barcelona's bench was a rare sight as he rested up for Milan. It was just the second time he didn't start a league game this season. In September, he went on late to score twice in a 4-1 win at Getafe. The only regular starters on the pitch for Barcelona were defenders Carles Puyol and Dani Alves and midfielder Cesc Fabregas.
Jose Pinto had a quiet night in goal after stepping in to replace Victor Valdes, who was serving the first of a four-match ban for protesting after the finish of Barcelona's 2-1 loss at Real Madrid last weekend.
Even with the lineup shuffle, the 51-point gap separating the two sides at the start of the game was evident. Barcelona dominated possession and broke its negative streak of conceding a goal in 13 matches in a row as Deportivo failed to get a shot on target through 90 minutes.
Only Daniel Aranzubia's inspired goalkeeping kept Deportivo alive as Barcelona midfielder Thiago Alcantara and young forward Cristian Tello poked holes in his team's defense.
Alexis finally broke through when Deportivo left him unmarked to turn Dani Alves' cross home with a bouncing header that Aranzubia got a hand on but couldn't keep out of his net.
The Camp Nou crowd cheered as Messi began warming up early in the second half, and the applause grew when he went on in the 62nd. Andres Iniesta and Sergio Busquets joined him later.
Just when the nerves among the home fans began to fray with Deportivo showing signs of life, Messi put everyone at ease by gliding across the edge of the box before combining with Alexis, who returned the ball from the wing for the cutting Messi to deftly flip it over Aranzubia.
"When we got the ball we lost it way too easily. We had problems linking together passes and just weren't able to do it," said Deportivo coach Fernando Vazquez. "I told Roura that at the level Barcelona is playing it doesn't seem impossible to me that they can rally against Milan."
Deportivo is a shell of the side that pushed Barcelona before succumbing to a 5-4 loss earlier this season.
The Galician club appears doomed to be relegated after just emerging from one season in the second division eight points from safety with 11 rounds to go. It is the only team in Spain's topflight division to have not won away from home this campaign.
In Valladolid, defender Martin Demichelis scored for Malaga in the eighth, only for Manucho to split the points in the 41st.
Malaga remained in fourth place, but opened the door for Valencia to grab control of the final Champions League spot if it beats Athletic Bilbao on Sunday.
Elsewhere, Rayo Vallecano beat visiting Espanyol 2-0 from goals by Alejandro "Chori" Dominguez and Francisco "Piti" Medina as the Madrid minnow stayed in upper part of the standings.
Mallorca edged Sevilla 2-1 at home after Alejandro Alfaro scored twice from rebounds of shots by Giovani dos Santos that hit the woodwork, lifting the team to within one point of safety.
Second-place Atletico hosts Real Sociedad on Sunday, while third-place Madrid visits Celta Vigo, and Getafe is at Levante.
Real Zaragoza hosts Granada on Monday. Real Betis downed Osasuna 2-1 on Friday.