Wales are the new IRB Rugby World Cup Sevens champions after an Aled Thomas try in the dying minutes helped them beat Argentina 19-12 in a thrilling men's Cup final at The Sevens stadium on Saturday.

Meanwhile, Shelly Matcham's extra time try saw Australia beat arch rivals New Zealand 15-10 to become the first nation to hoist the women's World Cup Sevens trophy.

However, it was the men's competition that dished out plenty of surprises on an enthralling final day.

Not even the most accurate of predictors could have foreseen the exits of four of the top contenders as New Zealand, South Africa, England and reigning champions Fiji all crashed out at the quarterfinal hurdle.

Kenya's 26-7 rout of two time champions Fiji, was easily the biggest shock of the day for a side who had never made it past the group stages in their two previous attempts.

But there was to be no repeat of their heroics when they took on Argentina in the semi-final as the South American side nailed a fairly comfortable 12-0 win.

If Kenya's run was a surprise, Wales were always the underdog in their last eight clash with New Zealand. And it looked to be going according to script till a try from Tom Isaacs late in the second half left Gordon Tietjens men stunned.

It was undoubtedly a turning point for the Welsh who then went on to quell a late challenge from Samoa to set up an intriguing tussle with the Argentineans.

The women's competition saw no such surprises as familiar names progressed to the knockout stages. But it was a bitterly disappointing day for the English overall as their women's team also failed to progress past the quarterfinals losing to eventual champions Australia. They were left to settle for the consolatory Plate trophy after beating Canada 12-0 in the final.

A packed crowd that had filled virtually every inch of the purpose built 50,000 capacity seater stadium were in full voice as the evening's two biggest matches approached.

Australia looked to be running away with the women's final as they raced to a 10-0 cushion before tries from Justine Lavea and Carla Hohepa brought New Zealand level. It took extra time to settle the exciting Trans-Tasman battle and Matcham proved to be the match winner with a storming run past the Kiwi defence.

“We came to this tournament just wanting to take it one game at a time,'' said a delighted skipper Chez Soon. Asked if beating their arch-rivals for the trophy makes it extra special, she said: “It sure does. The girls worked so hard to get here and it's all finally paid off.''

Few would have bet their money on Argentina and Wales contesting the Melrose Cup at the outset but the two nations produced an entertaining finale to the three day spectacle.

The two teams had met in the Pool stages with the South Americans coming out on top on that occasion. This time, they found themselves trailing 12-7 at the interval before Gonzalo Camacho's try five minutes into the second half kept their hopes alive. But there was yet another twist to the tale as Aled Thomas burst through the static Argentina defence in the final minute to send the Welsh fans into raptures.

“It is a massive statement,'' said Wales coach Paul John. “We have worked for three to four years to get to this point and everyone back home is really proud of us.''

Victorious skipper Lee Beach described his feelings on the famous win saying: “It's massive for me personally. This is something no one can take away from you as the sevens is the next big thing to the 15s.''