Racing Santander have edged ahead in their Copa del Rey quarter-final against Osasuna.
The first leg of their last eight encounter took place at El Sardinero on Thursday, with the hosts prevailing 2-1.
It took 60 minutes for the cup clash to spring to life, before there was a flurry of late activity.
Gonzalo Colsa broke the deadlock on the hour mark, before Papa Diop stepped off the bench to add a second for Racing six minutes from time.
Another substitute, Osasuna's Walter Pandiani, then handed the visitors a lifeline after 88 minutes, ensuring there will be all to play for in the return meeting.
Atletico Madrid would have expected to make light work of second tier opposition at Vicente Calderon, but they were held to a surprise draw by Celta Vigo.
The capital club have endured a disappointing campaign so far, but their progress in the cup had offered welcome relief.
They are, however, now sweating on a place in the last four after playing out a 1-1 draw with Celta.
The visitors gave an early signal of their intent when they took the lead after just three minutes through Roberto Trashorras.
Tiago did level for Atletico on 11 minutes, but they were unable to force a further breakthrough.
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