Ancellotti unhappy at Ronaldo red card
The recently crowned Ballon d'Or winner was given his marching orders 15 minutes from time, with the score already at 1-1, for appearing to hit out at Gurpegi after having a penalty appeal turned down.
The away draw leaves Real three points behind La Liga leaders Atletico Madrid, who moved to the top of the table with a 4-0 win over Real Sociedad earlier on Sunday.
Ronaldo is now likely to be banned for another crucial league encounter against Villarreal next weekend and Ancelotti wasn't convinced his star man deserved to see red.
"I think it is difficult for me to judge because I wasn't there, but the images show that it was an exaggerated reaction," said the Italian.
Brazilian defender Marcelo was stronger in his criticism of the decision.
"It is hard when you lose a player in an unjust manner. It is obvious that the decision wasn't fair and that made it very difficult, although our intention is to win every game," he told Spanish TV station Canal Plus.
"Athletic are a very good team, but we had bad luck today."
After withstanding some intense pressure from Athletic in the opening 45 minutes, Madrid looked set for an 11th consecutive victory in all competitions as Ronaldo's cross was turned home by Jese Rodriguez.
However, a stunning strike from Ibai Gomez brought the hosts level before Ronaldo clashed with Gurpegi.
Madrid then had Diego Lopez to thank for salvaging a point as the keeper tipped over another dipping effort from Gomez before denying Aritz Aduriz late on.
"The game was difficult for both teams," added Ancelotti.
"In the first-half Athletic pressed a lot and that made it difficult to play the ball on the ground so we played more on the counter-attack.
"In the second-half, the intensity of their pressure dropped a bit and we played better in possession, we scored and had good control of the game.
"Bilbao scored a fantastic goal, but in general I personally am satisfied with how Real Madrid played."
Following Barcelona's shock 3-2 defeat at home to Valencia on Saturday, Atletico took advantage of the Catalans slip up to become outright leaders for the first time since they won the league in 1996.
On an emotional evening at the Vicente Calderon as former players and the paid homage to former Spain and Atletico player and manager Luis Aragones, who died on Saturday, David Villa settled the early nerves as he turned home the opener eight minutes form half-time.
And after a spirited challenge from Sociedad after the break, three late goals from Diego Costa, Miranda and Diego Ribas propelled the hosts into top spot.
Coach Diego Simeone, however, continued to deflect attention from Los Rojiblancos' chances of going all the way in the title race, preferring to concentrate instead on his side's meeting with Real Madrid in the Copa del Rey on Wednesday.
"The objective is clear: the next game. Now we have the Copa del Rey on Wednesday.
"We need to recover and see how far we can go. After that we need to keep recovering after every game because we are playing every three days. It will take a huge effort, but we will see how we deal with it."
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