Having equalised just before the break, Los Che were sitting pretty but they shipped two goals within nine minutes of the restart and now have plenty of work to do at Mestalla
Los Che were tied at one goal apiece in the Spanish capital, with Jonas having cancelled out Radamel Falcao's opener for the home side, but they were left reeling after conceding twice in the space of five minutes just after the restart, with Miranda and Adrian both netting for the Rojiblancos.
While Valencia did manage to keep the tie alive with a late strike from Ricardo Costa, after Falcao had made it 4-1 to Atletico, Soldado admitted that Unai Emery's men have left themselves with much to do in next week's second leg at Mestalla.
"The start of the second half was very bad for us," the Spain international told Mediaset. "We did not work hard enough, defensively or offensively.
"In a game of this type you must give 100 per cent throughout and we did not do that. Atletico Madrid played very well with the players they have up front, but it's a bad result for us.
"Our fans will now be essential for us in terms over overturning his result, just as Aletico's fans were crucial for them tonight."
Valencia must now tackle Real Betis in La Liga before welcoming Atletico to Mestalla for next Thursday's return leg.