New Zealand have been overwhelmed 26-7 by Fiji in their semifinal of the IRB world sevens rugby tournament in Las Vegas.

Coming off the high of their triumph at the Wellington tournament last weekend, Gordon Tietjens' men were shut out by the rampant Fijians who had previously failed to fire a shot in the world series.

However, Fiji couldn't lift for the final, where they were well beaten 24-14 by South Africa.

The South Africans dominated the final, racing 19-0 up inside six minutes, with key playmaker Cecil Afrika crossing after just 46 seconds.

Fiji fought back to 19-14 but Bernardo Botha's try 3min from the end secured an upset win that keeps fifth-placed South Africa within sight of series co-leaders New Zealand and England at the halfway stage of the eight-leg series.

Earlier, New Zealand found themselves down 14-0 following a thrilling try to Joeli Lutumailagi three minutes after the halftime hooter had sounded, landing a body blow to their chances of reaching the final.

Mitieli Nacagilevu pushed Fiji further clear after the break, effectively sealing the result.

Veteran playmaker Tomasi Cama nabbed New Zealand's lone try with just over a minute remaining but Fiji had the final say courtesy of Nikola Matawalu.

The error-strewn New Zealand display followed an excellent first-day performance, including a 47-7 thrashing of Argentina in the quarterfinals.

England remain locked with New Zealand atop the standings after blowing a 10-0 lead against South Africa in their semifinal, going on to lose 17-10.

The IRB series moves next to Hong Kong on March 25-27.

Stuff.co.nz