Switzerland rewrote history by winning a knockout match at the 2026 World Cup for the first time in 88 years, beating Algeria 2-0 on Friday morning.
Mahrez, a five-time Premier League title winner, was subbed off in the second half with 20 minutes to go and revealed after the game that the defeat would also be his final appearance for the national team.
"The goal was to progress, and I think it was a game that was within our reach," Mahrez said. "We conceded two goals on mistakes, and at this level, we pay dearly for that."
"It's my last appearance even with the national team. It was my last game."
The 35-year-old forward retires with the second-most appearances for Algeria (119) and the second-most goals (40) in what was an incredible international career.
Mahrez was a part of the Algerian team that won the 2019 Africa Cup of Nations, and he departs international football with his head held high despite the World Cup exit this week.
He will now fully focus on Saudi Pro League side Al-Ahli as he sees out the final years of his career which saw him become a Leicester City and Manchester City legend.