Oriol Riera gave Osasuna a shock lead against Real Madrid in Saturday's Liga clash.
The centre-forward planted a 16th minute header past Diego Lopez.
He then doubled the hosts' advantage by nodding home after a corner was not dealt with.
The brace came after Cristiano Ronaldo missed an early sitter.
However Isco reduced the deficit to leave Real trailing 2-1 at half-time.
Then the capital giants equalised 10 minutes from via a Pepe header.
The Osasuna-based club are down at 16th in the table.