Barca have now gone three games without a LaLiga win having picked up five points out of a possible 21, suffering defeats by Leganes and Las Palmas in their previous two home games. They are three points behind Atletico having played a game more.
Pedri sent the Catalans ahead but second-half goals from Rodrigo De Paul and Alexander Sorloth helped Diego Simeone's side move three points clear at the top of the table, having played one match fewer than Barca.
Diego Simeone's red-hot Atletico are one of the most in-form teams in Europe on an 11-game winning streak in all competitions and looking like a well-oiled machine with Antoine Griezmann, Julian Alvarez and Rodrigo de Paul firing on all cylinders.
La Liga leaders Barcelona stumbled 1-0 at home against Leganes on Sunday as they suffered another blow in the Spanish title race.
Diego Simeone's side have been in fine form and continued their winning run across all competitions with a deserved home triumph, pulling provisionally level with league leaders Barcelona.
Real missed the chance to move above leaders Barcelona in LaLiga as they stay second on 37 points from 17 matches, one behind the Catalans who host Leganes on Sunday when Atletico, in third place on 35 from 16 games, welcome Getafe.
The 23-year-old was forced off with a muscle injury in their 4-0 thrashing of Osasuna at the Bernabeu earlier in November
"We changed the position of the forwards, with Mbappe outside and he did well, like Vinicius inside," said Ancelotti.
Raphinha and Robert Lewandowski's goals put the Catalans in a healthy position but Marc Casado's red card in the 82nd minute helped Celta start the fightback to snatch a point.
Real Madrid welcome Atletico Madrid for the first leg of their Champions League semifinal on Tuesday hoping to do something that has been beyond the reigning 11-time European champions for six decades.
Real Madrid thrashed Deportivo La Coruna 6-2 to stay level with Barcelona at the top of La Liga on Wednesday after the Catalans crushed Osasuna 7-1, condemning the minnows to relegation.
An under-strength Real Madrid crush Deportivo La Coruna 6-2 to pull level on points with Barcelona at the top of La Liga.
Villarreal kept their slim hopes of Champions League football next season alive as Roberto Soriano's late winner shocked Atletico Madrid 1-0 at the Vicente Calderon on Tuesday.
Atletico Madrid suffered a first defeat in 13 games in all competitions as they lost 1-0 at home to Villarreal on Tuesday after a late strike from substitute Roberto Soriano.
Atletico Madrid are waiting to find out if they will be allowed to sign new players in June after pleading their case over a FIFA-imposed transfer ban at the Court of Arbitration for Sport on Monday.
Lionel Messi scores his 500th Barcelona goal with the last kick of the game in a thrilling 3-2 win at Real Madrid.
Antoine Griezmann's second-half strike was enough for under-par Atletico Madrid to beat Espanyol 1-0 on Saturday, tightening their grip on third place in La Liga.
Isco struck at the death to send Real Madrid six points clear of Barcelona at the top of La Liga after twice coming from behind to beat Sporting Gijon 3-2 on Saturday.
Real Madrid defender Pepe has broken two ribs after colliding with team mate Toni Kroos during the 1-1 derby draw with Atletico Madrid on Saturday, the La Liga leaders said in a statement.
