Hayes, who has been in charge of the Blues since 2012 and signed England’s Chapman in 2014, felt the defensive midfielder was “the best player on the park” as her side beat Arsenal 3-1 in front of a competition-record crowd of 45,423 at Wembley.
“For someone chasing a 10th winners’ medal, she led by example,” Hayes added. “She was dominant and outran their midfield at times.
“What Katie has in abundance is composure under pressure. It’s about managing the biggest games on the biggest occasions. Katie’s done that throughout her career.”
Hayes joked that Chapman was “a greedy little cow” for winning a 10th cup as she praised the veteran of 94 senior international caps.
The former Arsenal assistant coach – who is 33 weeks pregnant with twins – believes Chapman, a mother of three, has seen her endurance improve since giving birth.
“Katie is insistent that, due to the birth of her three children, she runs more and more,” Hayes added.
“Everybody who has become a mother tells me that it increases your red blood cells, so you become better endurance runners.
“She’s in impeccable shape. She, physically, is probably our most dominant athlete.
“You can be that and not anything else, but it’s the quality she has – as a leader, a person and a footballer.”
Los Angeles Galaxy left-back Ashley Cole, with seven, holds the record for the most FA Cup wins as a player in the men’s game, after successes with Arsenal and Chelsea.
Former Fulham and Charlton star Chapman has captained Chelsea to cup success twice in the past four years and previously scored the winning goal in two finals, but says she enjoyed this year’s triumph as much as any other.
“It doesn’t get any better than winning the FA Cup,” she said. “I’ve got 10 and every single one is special and has a special moment. This was no different, up there among the very best.”