Switzerland's Breel Embolo scored the only goal against Cameroon - the country of his birth - in a hard-fought World Cup Group G opener.
Embolo refused to celebrate when he finished off a slick Swiss attack shortly after half-time.
The Indomitable Lions were unfortunate to lose after an enterprising display at the Al Janoub Stadium in Qatar.
Victory was vital for Switzerland, as both sides still have to face Brazil in the group.How the game unfoldedFifa World Cup: Groups & ScheduleWorld Cup TV Coverage guide
Embolo moved to Switzerland from Cameroon with his family as a six-year-old and pledged his allegiance to the European nation after being granted citizenship in 2014.
At the age of just 18, he set up the Embolo Foundation to support refugee children in Switzerland and disadvantaged children in the country of his birth.
He said before the game it would be "a very special" occasion to play against Cameroon and when he scored, he respectfully raised his arms and closed his eyes.
His strike ensured victory for a side with high expectations - boss Murat Yakin has declared his squad "the best Switzerland side ever" and said he expects them to achieve their best return at a World Cup.
Yet they struggled in the first half in the face of a vibrant Cameroon start and ought to have gone behind, with Eric Choupo-Moting, Bryan Mbeumo and Martin Hongla all missing presentable opportunities.
The goal rocked Cameroon and the Swiss had chances to extend their lead, only for Andre Onana to save superbly from Ruben Vargas, while Embolo and substitute Haris Seferovic were denied by last-ditch defending.
The Indomitable Lions have now lost eight successive games at the World Cup finals but Rigobert Song's side impressed at times here.
Their next game against Serbia will be pivotal if they are to stand any chance of becoming the first Cameroon team to progress beyond the group stage since 1990.
For Switzerland, the win gives them breathing space before their match against group favourites Brazil on Monday.
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Squad number1Player nameSommer
Squad number3Player nameWidmer
Squad number5Player nameAkanji
Squad number4Player nameElvedi
Squad number13Player nameRodríguez
Squad number8Player nameFreuler
Squad number10Player nameXhaka
Squad number23Player nameShaqiri
Squad number15Player nameSow
Squad number17Player nameVargas
Squad number7Player nameEmbolo
Squad number9Player nameSeferovic
Squad number18Player nameCömert
Squad number19Player nameOkafor
Squad number20Player nameFrei
Squad number25Player nameRieder
Squad number23Player nameOnana
Squad number19Player nameCollins Fai
Squad number21Player nameCastelletto
Squad number3Player nameNkoulou
Squad number25Player nameTolo
Squad number8Player nameAnguissa
Squad number14Player nameOum Gouet
Squad number18Player nameHongla
Squad number20Player nameMbeumo
Squad number13Player nameChoupo-Moting
Squad number12Player nameToko-Ekambi
Squad number5Player nameOndoua
Squad number6Player nameNgamaleu
Squad number7Player nameNkoudou
Squad number10Player nameAboubakar
Formation 4-2-3-11Sommer3Widmer5AkanjiBooked at 83mins4ElvediBooked at 64mins13RodríguezSubstituted forCömertat 90'minutes8Freuler10Xhaka23ShaqiriSubstituted forOkaforat 72'minutes15SowSubstituted forFreiat 71'minutes17VargasSubstituted forRiederat 81'minutes7EmboloSubstituted forSeferovicat 72'minutes
Formation 4-3-323Onana19Fai CollinsBooked at 36mins21Castelletto3Nkoulou25Tolo8Anguissa14Oum Gouet18HonglaSubstituted forOndouaat 68'minutes20MbeumoSubstituted forNgamaleuat 81'minutes13Choupo-MotingSubstituted forAboubakarat 74'minutes12Toko-EkambiSubstituted forNkoudouat 74'minutes
Match ends, Switzerland 1, Cameroon 0.
Second Half ends, Switzerland 1, Cameroon 0.
Manuel Akanji (Switzerland) wins a free kick on the right wing.
Foul by Georges-Kévin Nkoudou (Cameroon).
Corner, Switzerland. Conceded by Jean-Charles Castelletto.
Attempt blocked. Haris Seferovic (Switzerland) left footed shot from the centre of the box is blocked. Assisted by Fabian Rieder with a headed pass.
Corner, Switzerland. Conceded by Nouhou Tolo.
Substitution, Switzerland. Eray Cömert replaces Ricardo Rodríguez.
Foul by Gaël Ondoua (Cameroon).
Fabian Rieder (Switzerland) wins a free kick in the defensive half.
Attempt saved. Granit Xhaka (Switzerland) left footed shot from outside the box is saved in the bottom right corner. Assisted by Noah Okafor.
Foul by Moumi Ngamaleu (Cameroon).
Ricardo Rodríguez (Switzerland) wins a free kick in the defensive half.
Manuel Akanji (Switzerland) is shown the yellow card for a bad foul.
Foul by Manuel Akanji (Switzerland).
Frank Anguissa (Cameroon) wins a free kick in the defensive half.
Corner, Switzerland. Conceded by Nicolas Nkoulou.
Substitution, Cameroon. Moumi Ngamaleu replaces Bryan Mbeumo.
Substitution, Switzerland. Fabian Rieder replaces Rubén Vargas.
Foul by Fabian Frei (Switzerland).
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