Newcastle Falcons' Marcus Watson scored the decisive try for Team GB as they defeated Japan 21-19 on day one of the Olympic 7s in Rio.
The winger produced a fine individual try as Great Britain enjoyed an unbeaten start to the competition, having beaten Kenya 31-7 in their opening game.
Wednesday's schedule sees Team GB tackle world champions New Zealand at 4.30pm, New Zealand having been beaten by Japan in the shock result of day one.
