Germany and the European champions Spain put their reserves to the test as they both continued their preparations for the finals and Joachim Löw and Vicente del Bosque have problems, although differing ones.
Löw saw his makeshift side given a torrid time by an eager Swiss outfit who secured a 5-3 victory, thanks to Eren Derdiyok's hat-trick. Germany, without eight Bayern Munich players, were poor in defence, lacked their usual spark in attack and passed sloppily. Mats Hummels, André Schurrle and Marco Reus scored for Germany but Löw, who will announce his final squad next week, admitted: "We made far too many mistakes."
For Del Bosque, the problem is a much happier one. Without David Villa, who will not recover from his broken leg in time, he also had no Barcelona players, who were winning the Spanish Cup 3-0 against Athletic Bilbao. Pedro, who is keen to press for a starting place, scored twice in that game.
One of those given a chance by Del Bosque was Adrian Lopez. He came on for the second half and within 18 minutes had found a way through Serbia's massed defence, heading in a cross by Jesus Navas, to set Spain on their way to a 2-0 victory. Until that point the Serbs, under Sinisa Mihajlovic for the first time, had made Spain struggle to find a rhythm. Lopez further endeared himself to Del Bosque by winning the penalty with which Santi Cazorla wrapped up victory.
Roberto Soldado and Alvaro Negredo were also given a chance to show what they could produce, but neither managed to produce their best work.
Del Bosque will name his final 23-man squad today. "It's always good to have new players, it gives us more depth to our squad," Del Bosque said. "Adrian did very well, as did the rest of the players. We'll try to be fair when we make the decision."
Attack may be the best form of defence for Holland after their coach, Bert van Marwijk, turned to an 18-year-old newcomer, Jetro Willems, to fill the troublesome left-back position.
Van Marwijk can call on the leading scorers in the Premier League, Arsenal's Robin van Persie, and in the Bundesliga, Schalke's Klaas-Jan Huntelaar, and has a host of star names in midfield, but his defence is seen as a frail unit to put up against Portugal, Germany and Denmark in the group stage.
Van Persie, who has struggled to make his mark on major tournaments in the past, scored yet again, giving Holland the lead just before half-time. But Bulgaria equalised from the penalty spot through Ivelin Popov five minutes after the restart, and secured a 2-1 victory with a winner in the last minute from Iliyan Mitsanski.
Denmark, who play in Germany's group, were beaten 3-1 in Hamburg by Brazil, for whom Hulk scored twice and created the other goal. The Danes were error-prone and their coach Morten Olsen will no doubt be reviewing their defensive operation after his players were responsible for their own downfall by gifting the ball to Brazil for each of their three first half goals. Nicklas Bendtner scored for Denmark.