A Portia Woodman try right on half time proved to be the difference between a semi-final slot and a disappointing exit.

New Zealand snuck into the semi-finals of the Rio Olympic sevens competition with a 5-0 win over a formidable USA side.

Woodman broke the deadlock on the stroke of halftime after displaying an impressive burst of speed on the outside to race 40m untouched to the tryline.

She was pretty pleased with how she played.


"Personally, I played to my strengths and was happy with how I performed my core roles," she said.

"Now we need to work on our strengths going forward in the competition."

The Kiwi team were reduced to six players mid-way through the second half when Tyla Nathan-Wong was yellow-carded for a late tackle.

It made for a tense few minutes as the New Zealand side repelled waves of the US attack, before Nathan-Wong entered the fray again with 30 seconds on the clock.

Woodman said there was no panic in the New Zealand camp.

"This is something we've practised for, so we were confident we could cope with the loss," she said.

"The key was that we stayed calm and adapted to having one less player really well."

Speaking about her own try, she gave a lot of credit to her teammates.

"Not sure where I got the ball from, but Kayla [McAlister] was on the inside. She's a threat on attack so they mark up pretty heavy on her," she said.

"That gives me plenty of space on the outside."

The former Northern Mystics netballer has rugby in her blood - her father is Kawhena Woodman, who played for the national team in 1986, and her uncle Fred Woodman, who played 14 matches for the All Blacks in 1980 and 1981.

New Zealand will meet Great Britain in tomorrow's semifinal, after the British team overwhelmed Fiji 26-7 in the earlier quarter-final.

Great Britain will pose a serious threat at New Zealand's tilt at the gold medal, having gone through pool play unbeaten and only conceding 10 points in their first four matches.

The signs are good for New Zealand though, as the USA were no push-overs - they drew with gold medal favourites Australia 12-12 earlier in the day.

Australia will meet Canada in the other semi-final win after beating Spain 24-0.

Canada took down France 15-5 in the other quarter-final.