England coach Stuart Lancaster praised the maturity of his young side after their battling win away to Ireland but warned that their next game, against France, will be a massive test.
Four penalties from Owen Farrell gave England a 12-6 win to leave them as the only unbeaten side in the Six Nations.
"I'm chuffed for Farrell, but also the whole team's maturity," said Lancaster.
"The stakes have always been high but they're even higher with France coming off a defeat. It will be massive."
England will go into the game at Twickenham in a fortnight's time as leaders of the Championship, while Les Bleus are still winless after losing at home to Wales on Saturday.
In contrast to their free-flowing 38-18 opening win over Scotland, England's victory against Ireland was a gritty performance in driving rain in the Irish capital on a pitch that cut up badly every time there was a scrum.
England led 6-0 at the break but two penalties from Ronan O'Gara pulled level before Farrell kicked his team to victory.
"I think we had a good first half, but at the start of the second we had a couple of turnovers that put us under pressure," Lancaster told BBC Sport.
"I think we grew in stature towards the end of the game and deserved our win. We hadn't won here for 10 years and we went and did it. We will take it.
"As a test of character it was right up there because of the quality of the Ireland side."
Saracens fly-half Farrell only turned 21 in September but he controlled the game for England with a variety of kicks from out of hand.
He also landed four penalties to see his side home but downplayed his achievement.
"If you practise enough it is only another kick and it's no different in the stadium," he told BBC Sport.
"It was a massive game and I'm really exited to come over here and get stuck into the game. The conditions weren't great but we rolled our sleeves up and got stuck in.
"The weather wasn't great but the little things helped you along and I thought we did the little things well out there."
England captain Chris Robshaw was keen to praise Farrell - but also stressed the all-round performance of his team.
"Credit to Owen Farrell who kicked his goals, but from one minute to 80 the squad were top notch," said Robshaw "We tightened the game up, ran down the clock and had to be smart. It's a great day.
"Farrell is brilliant at the moment. He's got a great repertoire of skills, but he's got a great team around him who keep pushing him to get better. We're not going to get carried away."