Great Britain steer clear of trouble after Japan stun New Zealand
Great Britain remained unscathed as shocks and drama unfolded all around them on a spectacular opening day of the men's rugby sevens tournament at Deodoro Stadium.
Britain narrowly avoided going the same way as New Zealand, who were victims of arguably the greatest shock in sevens history when Japan beat them 14-12, while they also lost World Cup winner Sonny Bill Williams to an Olympics-ending injury.
The Japanese, emulating the spirit of their 15-a-side team when they unforgettably beat South Africa at last autumn's World Cup in Brighton, were a conversion away from drawing with Britain, but the last-gasp kick was missed and Tom Mitchell's men held out for a 21-19 victory.
Two James Rodwell tries put Britain in the driving seat, but Japan had no intention of rolling over, and they fought back to level the contest through converted scores from Lomano Lemeki and Katsuyuki Sakai.
Marcus Watson, brother of England star Anthony Watson, then touched down to put the Pool C leaders back in front, only for Lemeki's second try to set up a nerve-shredding climax that narrowly saw Britain move towards the quarter-finals ahead of tackling New Zealand on Wednesday.
There were far fewer dramas earlier in the day as Kenya were despatched 31-7 - Dan Bibby (2), Mark Bennett, Dan Norton and Phil Burgess scored tries - but the stadium then rocked as New Zealand were stunned by Japan.
Great Britain head coach Simon Amor said: " It's the first day at the Olympics for everyone.
"It's been fascinating to see the build-up, the challenges over the last 10 weeks and seeing how they (British players) have faced those and adapted to them.
"For a team that has never played together, which is in effect what these 12 players are, we've done excellently today."
And reflecting on Japan's epic triumph against New Zealand, Amor added: " People who've watched sevens this year, you would be a brave person to predict any game.
"It's great for the fans, but tough for us players and coaches.
"We've seen just how good that Japanese team are - they are outstanding - and they deserved their win, like we deserved ours today.
"We now focus on tomorrow. The rollercoaster of sevens goes up and goes down, and so hopefully we can rest up nicely ahead of tomorrow.
"W e moved the ball nicely against Kenya, which was decent. We got our kick-offs nice against Japan, who are a dynamic team, but we need to get our decisions around the breakdown right, which is an area we need to work on ahead of New Zealand."
New Zealand, with Williams no longer part of their plans due to a partially-ruptured Achilles tendon that could possibly mean several months' sidelined, recovered to beat Kenya and avoid another upset, while Australia and the United States were in the same boat for their second games on day one following earlier losses against France and Argentina, respectively.
Australia, though, then encountered no difficulty against Spain, and the US - with Super Bowl winner Nate Ebner and rugby's fastest man Carlin Isles among their try-scorers - saw off Brazil.
And pre-tournament favourites Fiji, who are coached by Englishman Ben Ryan, looked seriously in the mood as they brushed aside Brazil before making it two wins out of two by seeing off Argentina, albeit a much closer contest at 21-14.
But the day unquestionably belonged to Japan, whose star player Lemeki said of their New Zealand scalp: " It is unbelievable.
"You never see a minnow come here and beat a team which is supposed to be a gold medal contender. I am still shocked, to be honest.
"As we played on, we started getting more confident and New Zealand started to struggle a bit.
"We thought if we kept moving the ball around, the big guys would tire somewhere, and they eventually did."