Before Wednesday's shock 1-0 result, the U.S. were the only team to have beaten pre-tournament favourites Spain in three and a half years, upsetting the European champions 2-0 at the Confederations Cup last June.
Switzerland had taken note of the Americans' strategy, doing exactly what experienced coach Ottmar Hitzfeld said they would: working their hearts out, defending with nine men and looking to sting the European champions on the break.
The result was proof of how a hugely talented team able to dominate possession for long periods can be undone by organisation, grit -- and a slice of bad luck.
Vicente del Bosque and his team repeatedly insisted they had learned from that surprise reverse to the U.S. in Bloemfontein last June but the script was worryingly similar at Durban's Moses Mabhida Stadium for Spanish fans.
Those hoping for a sparkling performance to match Germany's 4-0 thrashing of Australia on Sunday were sorely disappointed and Spain are now precariously placed ahead of their remaining two Group H matches against Honduras and Chile.
Del Bosque fielded a cautious-looking 4-5-1 formation and lone striker David Villa spent the first half isolated up front, with the technically-gifted midfield, marshalled by Xavi, stroking the ball around but lacking real penetration.
What chances they managed to create, both before and after Switzerland's 52nd-minute goal, were squandered, with Andres Iniesta and substitute Fernando Torres especially guilty of wasteful shooting.
MISERLY DEFENCE
They were unfortunate when Xabi Alonso's thunderous drive crashed off the crossbar but the Swiss goal was never seriously threatened after that, even in the desperate final minutes.
After Del Bosque threw on Torres, Pedro and Jesus Navas, in the second half they were essentially playing with four up front but the Swiss held firm.
With hindsight, the Spain coach may be asking himself whether it would have been more effective to deploy Cesc Fabregas, whose creativity and experience might have been the key to unlocking the tight Swiss defence.
While the toothlessness of the Spain attack will be a big worry, the defence is also certain to come under scrutiny.
Switzerland's winner came after some slapstick defending from both goalkeeper Iker Casillas and the normally faultless Gerard Pique.
The Swiss, who had only 37 percent of possession, almost caught Spain on the break again when Eren Derdiyok was denied by a post.
Although they picked up four yellow cards to none for Spain, the Swiss did well to maintain their discipline after Philippe Senderos was forced off with an injury and are well placed to make it through to the knockout round.
The Spanish performance, by contrast, fell woefully short of sky-high expectations, both at home and abroad, and means they could be on course to play five-times champions Brazil in the next round should they make it through as group runners-up.
