Breel Embolo was the match-winner in Group G’s opening game, as Switzerland beat Cameroon 1-0.
Cameroon had several good chances to take a first-half lead, with the African side starting the match very much on the front foot.
Eric Maxim Choupo-Moting missed a big opportunity after 14 minutes, breaking through the Swiss back line but seeing his shot saved by goalkeeper Yann Sommer.
Minutes before, Karl Toko Ekambi had also been prevented with a goalscoring chance but failed to convert.
Switzerland defender Steven Widmer then put in a great last-ditch tackle midway through the second half, preventing Toko Ekambi from almost certainly scoring.
The Swiss then had two chances themselves to score just before the break. Near-identical inswinging Ruben Vargas corners caused problems for the Cameroon defence, with Nico Elvedi and Manuel Akanji sending headers wide of the post.
Embolo struck for Switzerland early in the second half after good work from former Liverpool man Xherdan Shaqiri. The Swiss forward scored against the country of his birth, with muted celebrations following.
Switzerland appeared to take initiative after the opening goal and it took an instinctive save from Andre Onana after a close-range Vargas effort to keep the score at 1-0 on 66 minutes. Embolo then went very close from the resulting corner, only a key interception from Andre-Frank Anguissa preventing the Monaco forward from adding a second goal.