The Duke of Sussex joined rugby league fans at the Challenge Cup final in Wembley Stadium, in his first public engagement since the row over his use of private jets.
Prince Harry appeared in high spirits as he met young mascots, players and coaches ahead of the clash between Warrington Wolves and St Helens on Saturday.
Dressed in a navy blue suit and grey tie, he shook hands with both teams and stood to sing the national anthem before watching the match from the stands.
It came days after The Duke and Duchess of Sussex, who did not attend the game, faced heavy criticism for taking four private jet flights in 11 days on holidays to Ibiza and Nice.
Their use of jets led to accusations of hypocrisy because the couple have previously expressed a commitment to protecting the environment.
The BBC's fact-checking team has calculated that the Duke and Duchess's two return flights by private jet would have created 37 tons of CO2: "more than six times an average Briton's yearly emissions, or 111 times those of a person in Lesotho".
Famous friends of the royals, including Elton John and the US talkshow host Ellen DeGeneres, rallied to their defence, saying they are"trying to make the world better".
Sir Elton, 72, claimed they had been subjected to "relentless and untrue assassinations" after being photographed with their baby son Archie Mountbatten-Windsor boarding a private jet heading to his mansion in the south of France.
The I'm Still Standing singer, a close friend of Princess Diana, said he had paid for their flight to France and paid for “carbon credits" to offset any CO2 emissions.
But the controversy continued when it emerged that the Duke and Duchess of Cambridge and their three children flew to Scotland on a £73 Flybe flight.
Both the Cambridge and Sussex families have used private and commercial flights in the past.
The Duke and Duchess of Sussex flew with Qantas on a long-haul trip to Australia for their first tour as a married couple, and joined members of the public on Royal Air Maroc for a trip to Morocco in the spring.
Princes William and Harry have regularly used economy airlines for short-haul flights and have been seen on easyJet, Ryanair, Wizz Air and Flybe as well as British Airways.