Switzerland edged past Cameroon 1-0 courtesy of a goal against the run of play by Cameroon-born Breel Embolo on Thursday for an opening win in World Cup Group G.
Embolo, born in Yaounde but raised in Basle, struck three minutes after the restart from Xherdan Shaqiri's cutback to put them top of the section.
The 25-year-old refused to celebrate the goal as the small group of Swiss fans cheered wildly at Al Janoub Stadium.
Serbia play Brazil in the other group match later on Thursday.
The Swiss goal came after Cameroon, without a win in the World Cup for 20 years, had dominated the first half, missing several good chances to take the lead.
The Indomitable Lions, who eliminated Algeria in a playoff to qualify for the tournament, had outplayed the Swiss in the first 45 minutes with quick combinations, speed and power as their opponents remained toothless up front.
They carved out their first chance after 10 minutes with Bryan Mbeumo testing goalkeeper Yann Sommer before Karl Toko Ekambi sent his rebound over the bar.
The Swiss were in trouble again a little later with in-form forward Eric Maxim Choupo-Moting snatching the ball from an opponent to charge into the box only for Sommer to block his effort.
In search of their first win at a World Cup in 20 years, Cameroon were bolder, taking on their opponents in one-on-one situations, while the Swiss rarely managed to get into their opponents' box.
Switzerland, who reached the round of 16 in the two previous World Cups, struck at the start of the second half with Xherdan Shaqiri cutting into the box and Embolo tapping in what proved to be the winner.
An almost identical move just past the hour almost saw the Swiss score again but Ruben Vargas's shot was pushed wide by keeper Andre Onana who kept his team in the game.
The Swiss next play Brazil on Monday with Cameroon taking on Serbia.
"I hope we can score a lot of goals."