In the top division France's 18-12 victory over South Africa ensured them of a second place finish in the top pool behind New Zealand, whose earlier 30-5 victory over Australia had given them maximum points from the pool stages.
France will now play third placed England in the semi finals, with New Zealand facing South Africa in a replay of last year's final.
Below the top four places Wales finish fifth, having secured a vital bonus point in winning 27-15 against Argentina.
Aled Brew's last gasp try not only ensured Wales took a bonus point, but also cruelly deprived Argentina of the bonus point they would have received for losing by seven points or less. As a result Argentina finish in ninth place, just behind Australia (sixth), Japan (seventh) and Scotland (eighth).
Japan, who had already received four points from the bye they received for their cancelled match with Ireland, beat Georgia 24-9, while Scotland recorded their first win, 35-5 over Italy.
In the second division Romania beat Russia 34-3 to finish top. The other unbeaten side, Uruguay, beat Tonga 22-14 to finish second. The two must be favourites to proceed to the final of the division.
Chile beat Canada 21-18 to finish fourth and face a testing semi final against Romania while Portugal overpowered Thailand to win 52-10 and finish eighth.
Namibia are dark horses for promotion to the top division after they came back from their opening day disappointment to finish third courtesy of a 43-22 win over Korea and book a place in the semis, where they will meet Uruguay.
The USA finally got their first win of the championship, beating Morocco 14-10 in a match which saw the teams clap each other off and pose for joint photographs.