Finn Russell's three missed conversions proved costly as England hung on for a 16-15 victory over a valiant Scotland side at Twickenham.
Ireland remain on course for a Six Nations Grand Slam but survived a huge scare against a much-improved Wales before completing a 27-18 victory at the Principality Stadium in Cardiff.
Wales have announced the departure of head coach Warren Gatland with immediate effect after a run of 14 successive Test defeats.
The second round of the Six Nations resulted in two changes to the top 20 of the World Rugby rankings.
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.