Kelly channelled Chastain when she took off her shirt after scoring in last Sunday's 2-1 win over Germany, with the iconic moment praised by the retired US player who did the same after her decisive penalty in the 1999 World Cup final against China.
Chastain tweeted to Kelly after the match saying she should enjoy all the "free rounds of pints and dinners" that come her way, before reminding her of the magnitude of her achievement.
"I said in a separate note to her that this will be with you for the rest of your life and whatever it is, the story is yours only you can tell it... you're the owner of it," Chastain said in an interview.
"Remain humble and remember you know what it took to get there. We've both had serious knee injuries, we've been on and off the team and back, so we've shared similar experiences."
Chastain, who played nearly 200 matches for the US between 1988-2004 winning two World Cups and two Olympic gold medals, said she told Kelly to always remember her worth.
"It's very important that when people come to her with opportunities that she expresses her value and does not take less because she's a woman," Chastain said.
"People will try that and obviously, some 23 years ago it was much harder to say, 'No, I'm worth more' and for people to believe it. But now it's undeniable."
BREAKING MYTHS
Chastain said the images of herself and Kelly celebrating in sports bras had broken some myths about women, with both of them celebrated for their capability rather than being objectified.
"I've always believed that soccer is the leader in breaking down these cultural beliefs," Chastain said. "We have greater conversations because of it.
"There is this underlying current about what women should look like, how they should present themselves... hopefully with these two celebrations and being 23 years apart, we can see a common thread that 'yes these are strong, fit women'.
"But the message is more about embracing opportunity and being your best when the moment arrives. The messaging about women is changing and not just because of these two moments... but the hard work from women in every industry being able to stand up and have their voices heard."
Chastain said she will head to England soon to meet Kelly.
"We've had a good congratulations back and forth. I hope that's something we'll forever be connected by, obviously, but that we can also collaborate to do some good things," she said.
On Wednesday, England announced on Twitter that they have sold out every ticket at Wembley for a game against world champions USA in October.
