Australia, Kenya, Czechia and Madagascar will compete for the medals tomorrow with second seeds the USA sensationally out of contention.
The USA were beaten by Czechia and Madagascar in Pool B. The scale of the African nation’s 12-10 upset was seen in the players’ wild celebrations following their victory.
The results in Pool B also mean Spain are out of medal contention.
Pool A was also decided with one round of pool matches left to play as Australia and Kenya won their games against China and hosts Senegal.
The final pool matches - Australia face Kenya and Czechia take on Madagascar - on 3 November will determine the semi-final line-ups.
New Zealand, gold medallists in 2018, are not present to defend their title as they did not qualify for the competition. Therefore Australia are the favourites and top seeds, and recorded the most dominant result on the opening day with a 32-0 win over Senegal.
The competition began with a Pool A 12-5 match between Kenya and China with the latter's lack of discipline seeing the African nation capitalise. A yellow card was shown to Xinlei Guo after a series of penalties by China and being a player up Kenya scored through Evalyne Afande, which was the only score of the first half.
A beautiful solo effort from Michael Mmboga started the second seven minutes and another yellow card was given to China, this time for Yuyan Hu, with more repeated infringements. But Peng Songmei scored to give China a losing bonus-point.
Australia, who won gold in 2014, beat Senegal in the next match after tries from Te Rinajade Murray, Darci Mackay, Talia Berryman, Grace Buchanan and two from Mia Shelley.
Spain and Czechia got their tournaments underway with the first Pool B match seeing a tight second half make for an entertaining match. Czechia came out with the 35-17 win but both sides had standout scores; namely a wonderfully rapid try by Sofia Rodriguez and an amazing solo effort by Zuzana Svabova.
The final match of the first round of pool matches came between the USA and Madagascar. It was the closest game of the day with Sariaka Raveloarisoa scoring the winning try to see it end 12-10, the result somewhat of an upset.
After a break the pool games restarted with the hosts and Kenya locked in a scrappy and tense match as the score stood at 0-0 at half-time. Josephine Kerubo, Shaheen Sada and Afande scored to give Kenya the 19-0 win.
Australia also booked their spot in the final four with another victory, this time against China, despite a red card for Keira Callaghan. When down a player Australia struggled with three second half tries from China but Layne Prince made a huge play to seal the 21-15 win.
A close match saw Madagascar beat Spain 19-12, while Czechia overcame the USA 24-21 as the day’s action concluded.
The women’s competition will wrap up on 3 November with one more pool round followed by the placing matches and medal deciders.