Holders Atletico Madrid suffered a losing start to the defence of their UEFA Europa League crown after slumping to defeat at the hands of Aris Thessaloniki.
Spaniard Javito struck a brilliant winner midway through the second half for the Greek side, who kept their unbeaten European home record intact and burst Atletico's early-season bubble.
Atletico's confidence has been sky high after beating Inter Milan in the UEFA Super Cup and climbing to the top of the Primera Division table after winning their opening two league games, but they were brought back to earth at the Kleanthis Vikelidis stadium.
Neither side created much to worry the respective goalkeepers during a low-key first half, but there were a lot more goalmouth incidents after the break. Atletico, missing the injured Sergio Aguero, started the second period promisingly with half-time substitute Diego Costa looking dangerous.
However, after both sides had gone close a couple of times each, it was Aris who took the lead with a superb goal from Javito in the 59th minute. Picking up possession on the edge of the box, he chested the ball forward and then unleashed an unstoppable first-time volley with his left foot into the corner of the Atletico net.
Young Atletico goalkeeper David De Gea could do nothing about that and, with Aris' remarkable home record which has seen them never having lost in 21 previous UEFA matches in front of their own fans, the Rojiblancos knew they were in trouble.
Things almost got even worse for the holders 10 minutes later when Sergio Koke struck the far post following a mistake by De Gea, with Juan Valera producing a crucial block to deny Carlos Ruiz from the rebound.
Atletico gave Aris' defence some problems in the final 10 minutes but Costa was denied by home goalkeeper Michail Sifakis before the same player headed a gilt-edged chance over from five yards out. That was as good as it got for the Spanish side and De Gea saved his side from a heavier defeat when he superbly tipped over Koke's acrobatic volley.