Manager Martin Johnson looked forward to a "massive week" for England's World Cup prospects after his side's 67-3 rout of Romania.
If Scotland beat Argentina on Sunday, the Scots and England will both qualify, with the winner of their meeting next Saturday topping the pool.
If Argentina win, all three sides could still qualify for the last eight ahead of the final round of pool matches.
"It was job done and now we go into a massive week for us," said Johnson.
"The World Cup really starts in a way. That will be a scrap - hopefully [when Scotland play Argentina on Sunday] it will be an incredibly physical game!
"It's a mental thing this week, getting ourselves ready for the game. It's going to be a big one."
Johnson said he was pleased with the way England performed against Romania.
"These games can be awkward in a way but we kept our discipline pretty well," he said.
"Romania worked as hard as they could for 80 minutes and had a real crack at us. You have these games at the World Cup, but hopefully we have got off the field with no injuries so that's the main thing for us.
"Romania's priority may be Georgia in the week [their final pool match on Wednesday] and winning that game but they certainly came and had a crack. It's one of those games where things maybe break for you differently than it would do in other games, you've just got to keep your discipline and play some decent stuff."
England scored five tries in each half, Mark Cueto grabbing a quick-fire hat-trick in the first period before fellow wing Chris Ashton completed his hat-trick after the break.
Ben Youngs, Ben Foden, Manu Tuilagi and Tom Croft also got on the scoreboard in the second half as England produced a far more fluent display than the scratchy 41-10 win over Georgia last weekend.
"We looked at our performance last week, there was a lot to improve on and we did that today," said captain Lewis Moody.
"We've still got areas to work on but the performance was much better - that's what happens when we keep hold of the ball and do the basics right.
"We had a point to prove to ourselves and we went some way to doing that."
Cueto, making his World Cup bow after being sidelined for the first two games, scored more tries in 12 first-half minutes than he had in his previous 28 internationals.
"Obviously it's been a frustrating couple of weeks, I had a bit of a niggly injury which kept me out so to come back in an open game like that and get a hat-trick is good for the confidence," he confirmed.
Fellow hat-trick man Ashton admitted he was feeling left out as Cueto scored his treble, before grabbing two tries of his own before the interval and adding a third in the second half.
"I was getting a bit upset when he had three tries and I had none - but it's not all about the tries," said the Northampton winger.