The Tokyo 2020 men’s Olympic rugby sevens competition began in an exciting fashion with all 12 teams in action on the first morning of rugby sevens at Tokyo Stadium.
South Africa scored five tries to beat Ireland 33-14 and kick-off their Pool C campaign with a victory on day one.
Zain Davids opened the scoring for the Blitzboks before Impi Visser added a second try with less than six minutes gone.
Gavin Mullin got Ireland on the board before the break, but it was South Africa who struck first in the second half as Justin Geldud rose highest to claim a cross-field kick and dot down.
Terry Kennedy grabbed his first Olympic try to give Ireland hope of a comeback, but the Blitzboks made sure of victory with an expertly-taken Chris Dry effort and a late score from Stedman Gans.
South Africa will now take on Kenya in the final match of day one.
Defending champions Fiji needed to come from behind to get their Tokyo 2020 campaign off to a winning start against hosts Japan, eventually running out 24-19 winners.
In the other Pool B encounter reigning silver medallists, Great Britain got their campaign off to a winning start, with a 33-0 defeat of Canada with World Series top try scorer of all time Dan Norton scoring two tries.
Japan will begin the second competition session when they take on Great Britain at 16:30 local time (GMT+9) with the hosts looking for their first win. Canada will be looking to score their first points of the Games when they face Fiji at 17:00 local time.
In Pool A, Rugby World Cup Sevens and World Rugby Sevens Series champions New Zealand opened their Tokyo 2020 campaign with a win, beating the Republic of Korea 50-5.
The All Blacks Sevens will take on Argentina at 17:30 local time, and the South Americans warmed up for that match with an impressive 29-19 defeat of Australia.
In the final match of the morning session, Kenya slipped to an agonising 19-14 defeat to the USA.