0641 GMT August 24, 2019
The technology is making its debut in England's top flight this season and, after Friday night's curtain raiser between Liverpool and Norwich passed off without incident, it took center stage on Saturday, BBC Sport reported.
VAR was first called on when Gabriel Jesus appeared to have put City 3-0 up midway through the second half, only for Raheem Sterling to be ruled fractionally offside in the buildup.
After Sterling added City's third, a moment also reviewed for possible offside, the system then awarded the visitor a penalty retake after Sergio Aguero's tame effort was saved by Lukas Fabianski but Declan Rice was deemed to have encroached into the area.
The striker made no mistake at the second attempt.
This was, nevertheless, a dominant and deserved victory for Pep Guardiola's side, which laid down a marker for the season ahead in emphatic fashion.
The visitor had looked a little short of its best early on but it took the lead midway through the first half when Jesus flicked in Kyle Walker's low ball into the box.
The Citizens doubled their advantage six minutes into the second half, Sterling sliding in a low shot after being put through by Kevin de Bruyne.
After Jesus' VAR-denied effort, a third did come for City as Sterling ran on to a ball over the defense before coolly lobbing Fabianski. And after Aguero's retaken penalty, Sterling got his third in injury time to complete the rout.