Switzerland's super-sub Haris Seferovic says his side are 'hungry' for a World Cup win over neighbours France in Friday's key Group E clash after his last-minute winner against Ecuador.

The 22-year-old came off the bench to score in the last minute of injury time and seal Switzerland's dramatic 2-1 win in Brasilia last Sunday to cap a remarkable Swiss fightback.

Fellow substitute Admer Mehmidi had taken just 121 seconds after coming on at the break to cancel out Enner Valencia's first-half header for Ecuador.

Next up are Didier Deschamps' France in Salvador with the French also having opened their account with a comfortable 3-0 win over Honduras to top the group.

And Seferovic says the second-placed Swiss are eager to prove themselves against 'Les Bleus' at the Arena Fonte Nova.

"We have experienced players like (Napoli pair Valon) Behrami, (Goekhan) Inler and (Juventus' Stephan) Lichtsteiner. We're young and we're hungry," said the striker.

Having capped his World Cup debut with a goal, Seferovic is hungry for more.

"I had a lovely time, it gives you confidence and I was just happy to have scored," he said.

"The result allowed us to clear the first hurdle."

Seferovic, who plays for Spanish top tier side Real Sociedad, scored the winning goal in the Under-17 World Cup final for Switzerland against Nigeria in 2009, but says he is loving being on the big stage at 'the real World Cup'.

He expects an open game as the French led up front by the in-form Karim Benzema, who scored two in the opening win over Honduras, look to attack the Swiss.

"There will surely be more space (than against Ecuador) because the French like to play more. They are strong in attack, but it may be their weakness to want to attack too much," said Seferovic.

Seferovic will likely have his Real Sociedad club-mate and fellow striker Antoine Griezmann facing him and he has warned his Swiss team-mates to be wary of him.

"Griezmann is a very good player, he is a fox, cunning, insolent," he said.

"He knows where to run to, he never stays in the one place, and is definitely a player we need to pay attention to. But we have Stephane (Lichtsteiner, who is experienced and who will know what to do with regards to taking care of him."