Title rivals Barcelona and Atletico Madrid stayed locked together at the top of La Liga after they played out an intense 0-0 draw with few genuine chances at the Calderon on Saturday.
Not even the introduction of Barca's fit-again World Player of the Year Lionel Messi at halftime or Brazil forward Neymar with just over 20 minutes left could break the deadlock and both teams have 50 points at the halfway stage of the campaign.
"They are a very, very compact side, one of the best teams in Europe and physically very strong," Barcelona captain Xavi said in an interview with Spanish TV broadcaster Canal Plus.
"We had our chances but it was an extremely intense match and in the end a draw," added the Spain playmaker.
"Normally in the final 15, 20 minutes against them is when we finish stronger and have chances to score but it was a finely-balanced game and Atletico are a great team.
"They have a different style to us but defensively they are excellent and they allow you very little space."
The result was good news for third-placed Real Madrid, who can close to within three points of the joint leaders - Barca are top on goal difference - with a win at Espanyol, the only team to beat Atletico this season, on Sunday (1800 GMT).
Real lost 1-0 at home to Atletico at the end of September and went down 2-1 at Barca in October's "Clasico" but have not been beaten since then and are likely to be challenging for the title when the league reaches its climax in May.
Saturday's closely-fought encounter was similar to the home and away clashes between Barcelona and Atletico in the season-opening Spanish Super Cup, when they drew 1-1 at the Calderon in the first leg before the return at the Nou Camp ended 0-0.