Switzerland captain Alex Frei says the gap between traditional football powers and the rest of the world is shrinking.

The Switzerland striker pointed to defending champion Italy's 3-2 loss to Slovakia on Thursday, and says "there aren't just underdogs and favourites anymore."

Switzerland pulled off one of the biggest upsets of the tournament so far, beating European champion Spain 1-0 in its opener. It was only Spain's second loss in 50 games.

Despite that result, Frei warned not to discount the Spanish, who must beat Chile on Friday to advance to the round of 16.

"It would be disastrous not to look at Spain as a favourite," the 30-year-old striker said.

"Just take a look at the players they have, take a look at the football they play.

"I'm sure that they are going to put their foot down and leave their mark on this tournament."

Switzerland can secure a spot in the next round with a two-goal win over Honduras on Friday.

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