Byram was brought to West Ham from Leeds United earlier in the transfer window, and the youngster was thrown into Upton Park life at the deep end.
The 22-year-old was brought on in the early stages of West Ham’s 2-2 draw with City, following an injury to Carl Jenkinson, but he caught the eye on his first appearance.
And Payet said: “I shouldn’t think he was expecting to end up on the pitch so early. He absolutely did his job.
“I know he ended up with, I’m not sure what, slight cramp, I suppose, but his debut was very encouraging.
“It’s not easy to come on that early and it’s not easy against City and he had to deal with both! Congratulations to him.”
Byram had never played above Championship level before, but featuring in the top tier did not appear to faze him.
The right back coped with the pressure well, and played a key part in West Ham’s fixture.
Byram dealt with City’s attacking threats well, and only a Sergio Aguero double saved Manuel Pellegrini’s side from falling to a defeat.
West Ham’s draw with City has moved them into sixth place in the Premier League table - just six points back from the top four.