Eddie Jones was thrilled with England's tenacity in their hard-fought 12-6 win over Wales at Twickenham.
Jonny May ran in two tries in the opening 20 minutes to send defending Six Nations champions England on their way, before Wales' Gareth Anscombe had a try controversially disallowed by the TMO.
Anscombe's late penalty brought Wales to within a converted try of causing an upset but England dug deep to hang on and claim the victory.
"The win was built around a lot of courage and a lot of belief in the team," England head coach Jones said.
"I thought the execution of the game plan by the players was absolutely outstanding and our application of courage and effort in defence was first class.
"Following on from the win against Australia in November, it showed we can be in an arm-wrestle, we can hang in there, find a way to win and that is an important habit to have.
"You get that habit by working harder than other teams. We have to continually remember that.
"When you have success, it is easy to sit back and complacency sits next to you. It is important we keep doing those things and that allows you to win those arm wrestles."