Prince William failed to prevent his water polo team from losing in a tri-nations competition in Cardiff.
The 21-year-old student joined the Scottish national universities squad to compete for the Celtic Nations cup on Saturday.
He took to the pool to try and help his team-mates triumph over Ireland, but they eventually lost 14-7.
He had earlier been greeted by an enthusiastic crowd outside the Welsh Institute of Sport in Sophia Gardens.
It was the prince's international debut, with him appearing on the team sheet as William Wales.
His talents were not called on until the second quarter of the game, after spending the first quarter standing on the edge of the pool cheering his team-mates on.
Wearing black and grey Speedos, and a navy blue polo cap, he attracted loud support from Scotland's female swimmers when he helped to prevent the Irish scoring at one point.
But his efforts were not enough to hold back the Irish team, who had taken the lead straightaway.
The game is noted for being one of the most physically demanding team sports, with squad members frequently substituted.
William was called on a total of three times during the game, and suffered his share of duckings.
William playing water polo aged 18
The prince, who captains St Andrew's university's water polo team, is said to be an attacking player, but left the attempts at scoring in this match to his team's centre player.
There are 13 members in a water polo squad - seven in the water, including the goalkeeper, and six substitutes.
Before the game began, William had shaken hands with a group of wellwishers outside the venue and autographed programmes for a group of girls who had taken part in a trampolining competition.
Casually dressed in a black jacket, faded jeans and worn-in trainers, his appearance prompted Jo Morgan, 75, of Abertillery south Wales to remark: "I think he could do with a new pair of shoes or jeans or something."
The Scottish team also lost their second match to Wales, who won the overall competition.
Welsh captain Oliver Newcombe said William did not receive any special treatment.
"He played pretty well I think. The standard this year was very hard.
"We didn't single him out for any special treatment. Water polo is a hard sport to play," he added.