The USA opened up the first ever IRB-sanctioned women's international 7s event (aside from the 7s World Cup), beating South Africa 22-10 in the first game of the Dubai Women's International 7s in Dubai.
The Eagles have China and England left on their first day schedule.
Canada takes on Australia, Brazil and Spain.
IRB Chairman Bernard Lapasset said: “We have developed a clear policy with our Member Unions to focus on elite women’s competition ahead of Rugby Sevens’ debut in the Rio 2016 Olympic Games and today represents a significant step on the road to Rio de Janeiro for these international teams.
“Once again the women’s tournament will run alongside the men’s, as it did when we hosted the hugely successful Rugby World Cup Sevens 2009 here in Dubai, and we look forward to another memorable event this weekend.”
Australia captain, 2009 Rugby World Cup Sevens winner, Rebecca Tavo, said: "Playing this first IRB tournament feels like the start of a new era for the women's game and we are all extremely excited and honoured to be here in Dubai.
"Another World Cup is coming up fast in Russia and beyond that the Olympics and to have such a strong international field here is a sure sign of the future."
The IOC decision to include Rugby Sevens as an Olympic Sport for the 2016 and 2020 Olympic Games has provided a significant impetus to the Women’s Game, which is already enjoying record participation around the world.
“Together with our Member Unions we have always had a strong commitment to grow the Game but we now have a strategic goal to host exceptional events and provide a global competition framework to ensure the increased competitiveness and standards of elite Women’s Rugby,” said Susan Carty, IRB Women’s Development Manager.
“We look forward to an exceptional competition here in Dubai and further Women’s Sevens events held alongside the HSBC Sevens World Series in 2012 to help prepare elite players for Rugby World Cup Sevens 2013 in Moscow and ultimately the Olympic Games in 2016.”