US second lady Jill Biden was the star guest of Prince Harry on Saturday at the third day of the Invictus Games, a Paralympics-style event for wounded troops organised by the British royal.

The pair, both vocal supporters of the Armed Forces, watched a wheelchair basketball match at the Copper Box arena in east London's Olympic Park.

Harry, fourth in line to the throne, is a serving British army captain who completed two tours in Afghanistan, while Biden -- married to Vice President Joe Biden -- is a campaigner for forces' families in the US.

A total of 416 wounded troops -- both serving and veterans -- from 13 countries were welcomed to the inaugural Games by Harry at Wednesday's opening ceremony.

Other highlights of Saturday, the penultimate day of competition, were the rowing events with former Royal Engineer captain, Nick Beighton -- who lost both legs after stepping on an improvised explosive device in Afghanistan in 2009 -- claiming three gold medals.

"There was a real buzz out there. Everyone lifted their game but you try and tune it out a little but because you're trying to focus on what you're doing," Beighton said.

"It's given everyone the opportunity to compete, not just the Paralympians among us but right down to the people who have recently been injured. It's great to have a focus to get out there and do something."