Schär's side beat Bulgaria 4-0 in Lucerne, with the Newcastle United defender starting the game before coming off for Eintracht Frankfurt's Djibril Sow in the seventh minute of stoppage time.
Meanwhile his Magpies team-mate Lewis played the full match for Northern Ireland against Italy, who began the night at the top of Group C on goal difference.
But a 0-0 draw in Belfast saw Switzerland leapfrog the Euro 2020 winners, who will now have to battle through a play-off if they're to qualify for Qatar.
Lewis was solid defensively against Italy's attacking talent while also providing a constant outlet on the left, particularly in the second half when he crossed for George Saville, who brought a fine save from Gianluigi Donnarumma, and then for Stuart Dallas, who shot wide.
The point, along with Bulgaria's defeat, meant that Northern Ireland finished a creditable third in the group.