Erling Haaland has scored 67 goals in 70 appearances for Manchester City across all competitions
The Norwegian striker shrugged off the ankle injury that forced him off at half-time in Saturday's hammering of Bournemouth to clinically convert a 23rd-minute penalty after Sandro Lauper had fouled Matheus Nunes.
He then smashed home a second from the edge of the area six minutes after the restart, shortly before Lauper was sent off for a second booking following a foul on Nathan Ake.
In a bizarre exchange, Haaland had already handed his shirt over to Young Boys skipper Mohamed Ali Camara at the break when the Guinean asked for it as the players made their way to the tunnel.
By that point Phil Foden had added a second, finding the net after ollecting Jack Grealish's superb curling pass to the side of the penalty area and skipping past Ulisses Garcia.
The result sends City into the knockout phase for an impressive 11th consecutive season, and also means they have set a new record of 18 matches unbeaten in Europe for an English club.
The win also extended their run of home victories in all competitions in 2023 to 23 games, one short of the English record, set by Sunderland across 1891 and 1892.
Rivals Liverpool are the next visitors to this stadium, in the Premier League on 25 November. That game will almost certainly be far more competitive than this one was.
-- Courtesy of BBC Sport