The Duke of Sussex made a solo outing to watch polo in Montecito, California, attending without Meghan Markle by his side.
Harry, 41, was there to cheer on Artemio, the son of his longtime friend Nacho Figueras, during the match.
The royal opted for a relaxed look, wearing charcoal shorts paired with a black polo shirt featuring the number three.
He kept things understated with a baseball cap and sunglasses, choosing to sit barefoot on the ground while taking in the action.
A barefoot Prince Harry was spotted watching polo from the sidelines in Montecito (stock picture)
|GETTY
Neither his wife, 44, nor their children Prince Archie, seven, and Princess Lilibet, four, accompanied him to the event.
Artemio's team lost, though he claimed an award for best polo pony.
The Duke of Sussex and the Argentine polo star have maintained a close bond stretching back to 2007.
Throughout the years, the pair have competed together in numerous polo matches, forging a partnership both on and off the field.
Artemio Figueras pictured with his father, Nacho Figueras, in 2019
|GETTY
Mr Figueras, a model with an estimated fortune of $30million (£2million), has earned the nickname the "David Beckham of Polo" and has emerged as one of the most outspoken defenders of Harry and Meghan.
The friendship runs deep enough that Mr Figueras secured an invitation to the couple's wedding, having witnessed their romance blossom from its earliest days.
Mr Figueras has never shied away from publicly championing the Sussexes, declaring during a September 2019 appearance on Ellen DeGeneres's programme that he would defend his friends with his life.
That same year, he spoke warmly of the duke to Town and Country magazine: "What I like the most about [Harry] is how real he is and how serious he is about improving life for kids that have not had the blessings that we've had."
Prince Harry meeting Artemio as a baby in 2010 in New York
|GETTY
The polo player also shared an intimate moment from the couple's early courtship in the Harry & Meghan Netflix documentary, recounting how Harry confided in him and his wife, Delfina Blaquier, following his first date with Meghan in 2016.
"He looked at us and said: 'Guys, I met a girl, we've just met, but I think this might be the one,'" Mr Figueras recalled.
"You could tell right away that those eyes were those of someone who'd fallen in love."
Mr Figueras was among the select few to meet baby Archie in Windsor during 2019, an experience that clearly left a lasting impression on the Argentine sportsman.
Nacho Figueras and Prince Harry playing polo today in 2024
|GETTY
Later that year in December, he unveiled a collection of six fragrances inspired by his global travels, including one named 'Windsor' that he hoped would evoke "feelings of every kind of paradise."
A share of the perfume sales went to Sentebale, Harry's charity.
Following Archie's birth, Mr Figueras praised the duke's parenting abilities, describing him as "amazing" and noting his evident happiness in fatherhood.
"I've seen him interact with children for a very long time in all these things that we do in Africa, so I'm not surprised he's an amazing father," he said.