Foden was recently crowned Football Writers' Player of the Year for his best goalscoring season and ended any suspense after just 79 seconds.
The England international fired a thunderous drive into the top corner to ensure there was no nervous wait for the title party to begin.
Foden doubled City's lead inside 20 minutes with another superb left-footed strike from Jeremy Doku's cross for his 27th goal of the season.
“Not just me, all the players have played important games over the years and been in this situation many times, so it definitely helps the nerves,” Foden said.
“I thought we looked confident today and played football. It paid off in the end.”
Suddenly, the story of the first half took a turn when Mohammed Qudus's powerful overhead kick from a West Ham corner flew over Stefan Ortega.
City quickly restored order early in the second period and it was fitting that Rodri, himself a Player of the Year, delivered the knockout blow to Arsenal's title hopes.