Luis Suarez scored a dramatic late winner as Atletico Madrid fought back to beat Osasuna and put themselves on the verge of a first La Liga title for seven years.
Diego Simeone's side now travel to Real Valladolid in their final game knowing that a win will clinch the title.
Ante Budimir's header had put Osasuna on course for a shock win and seen Real Madrid briefly top the table.
But Renan Lodi levelled before Suarez steered in Yannick Carrasco's cross.
Both Atletico goals arrived in the final 10 minutes of a compelling contest - and just as it looked as though they were going to have to surrender top spot to their city rivals.