Real Madrid suffered a remarkable opening Champions League defeat as Shakhtar Donetsk, missing 10 first-team players due to coronavirus, held on for a 3-2 away win.
Wednesday's Group B clash seemed to be set up for a straightforward Madrid win, with Shakhtar clear underdogs even before losing half their squad to COVID-19 in a situation coach Luis Castro described as "a nightmare".
But Zinedine Zidane's LaLiga champions were outthought and outfought for 45 minutes at their temporary Estadio Alfredo Di Stefano home as strikes from Mateus Tete and Manor Solomon sandwiched a Raphael Varane own goal to secure a three-goal half-time lead.
Madrid also lost at home to Cadiz last Saturday and visit bitter rivals Barcelona in the Clasico this weekend yet at least showed some fight after the break.
Efforts from Luka Modric and Vinicius Junior set up a grandstand finish, but Federico Valverde's apparent equaliser in stoppage time was disallowed for offside as Shakhtar survived for a sensational victory.