Sanchez provided the cross for Arturo Vidal to head home their 81st minute opener and inspired the second goal as well. He beat the offside trap but failed to score. Eduardo Vargas was on hand to put the ball into the net in the dying seconds.
Vargas had the ball in the net as the match moved into stoppage time at the end of the first half, deftly lifting it over the onrushing Cameron goalkeeper Fabrice Ondoa after being expertly fed by a defence-splitting pass from Vidal.
Slovenian referee Damir Skomina initially awarded it but then, more than minute later, he suddenly reversed the decision on the advice of the VAR, Clement Turpin of France.
But Vargas was on the right side of technology for Chile’s second as Sanchez sprung the offside trap from just inside the Cameroon half to round the goalkeeper only to have his own effort blocked. Vargas followed up the rebound only to see the linesman’s flag shoot up.
But a quick check with the VAR found both Chilean players had been onside and the decision was reversed to confirm a two-goal winning margin
The African champions came closest when captain Benjamin Moukandjo hit narrowly wide with a shot from the edge of the penalty area midway through the second half.