Ireland asserted their Six Nations intentions with a comfortable 32-18 victory over Scotland at Murrayfield on Sunday.
England ended their long wait for a victory over a Tier 1 nation with a gutsy 26-25 win over France at Allianz Stadium on Saturday.
Italy secured a 22-15 victory over Wales at the Stadio Olimpico, deepening Wales' Six Nations woes with a 14th consecutive defeat and all but confirming their second successive Wooden Spoon.
Round two of the Six Nations could result in several changes to the official World Rugby rankings, with only Italy and Ireland unable to improve their current placing.
France flyhalf Romain Ntamack will find out his fate on Wednesday following the red card he received in the Six Nations opener against Wales.
The opening round of the 2025 Six Nations and Rugby Europe Championship has little impact on the official World Rugby rankings.