Eddie Jones insists England are "nowhere near good enough" despite seeing his side end a 10-year wait for a victory over South Africa with a commanding 37-21 win at Twickenham.
The Springboks had been unbeaten in 12 straight games against England, including the 2007 Rugby World Cup final, but saw that streak emphatically ended as they were outscored four tries to two on Saturday.
England's triumph was their 11th in succession and made it 10 out of 10 for Jones, who took over after their humiliating pool-stage exit at the 2015 World Cup.
Despite putting another southern hemisphere power to the sword - England whitewashed Australia in a Test series down under earlier in the year - Jones still believes they have a lot of work to do to become the best team in the world.
"When I took the job I had no expectations, all I knew was that I was inheriting a very good side that was put together by Stuart Lancaster that had oodles and oodles of talent," Jones told a media conference.
"My job was to make sure that talent produced performance, we're starting to do that but we've got to get better, we're nowhere near good enough at the moment."
England began to take control in the latter stages of the first half, scoring 13 points in the final six minutes of the period, to lead 20-9 at the interval.
Asked about the way England assumed command, Jones added: "My job is to make myself redundant. When I'm redundant then the team is going to be functioning well.
"To win by that scoreline is fantastic, we're certainly not satisfied with our performance, [there are] areas of our game that really need tidying up.
"We've got 10 of the squad that went to Australia not here so we've had to put together a new team, get people to understand how we want to play and we always thought the first 20 minutes was going to be the most difficult.
"We regained our composure, control, some of our attack was good and some was very poor. Defensively we gave away a soft try at the end, which was disappointing, but all in all we get a pass mark."