England wary of Wales in 'open' Six Nations
England's Ben Morgan (L) evades a tackle from Ireland centre Brian O'Driscoll during their Six Nations rugby union match, at Twickenham in west London, on February 22, 2014 - by Glyn Kirk
Saturday's success saw England hold their nerve and match a powerful Irish pack as they came from 10-3 down early in the second half to win following a well-worked try scored by scrum-half Danny Care.
Victory left England level on four points with Ireland, Wales and France.
Wales, bidding to win an unprecedented third successive outright Six Nations title, got their season back on track with a 27-6 win over France in Cardiff on Friday following a thumping 26-3 loss away to Ireland.
"The Six Nations is open for everyone given the way the results have gone. It's been a fantastic championship this year," England coach Lancaster said.
"We'll enjoy this win but we know that there's a big, big challenge coming in two weeks' time."
Victory over Wales would give England the Triple Crown, having beaten all three ofthe other Home Nations.
But the ever-cautious Lancaster, whose side were thrashed 30-3 by the Welsh in last season's title decider, said: "We respect Wales because of what they've achieved over the last couple of years and their performance against France has given them confidence, so it will be a great game."
Ireland, on a day when star centre Brian O'Driscoll made a world record-equalling 139th Test appearance, led by seven points early in the second half after full-back Rob Kearney's try caught England cold.
- 'Absorb pressure' -
"Ireland had a very strong period at the start of the second half and it was at that point that our confidence and self-belief shone through," said Lancaster.
"We came back and scored a fantastic try ourselves and I thought the defining moment was the 77th to 79th minutes when we were defending and our character shone through.
"We learnt to absorb pressure and not panic."
No side in this season's Six Nations can now win a Grand Slam but Ireland remain in pole position for the title given they have a points difference of +42 compared to England's +21, Wales' +6 and France's +1.
The Irish will be firm favourites to improve that advantage when bottom-of-the-table Italy come to Dublin on March 8 for what should be O'Driscoll's final home Test before he retires at the end of the season.
Italy suffered a heartbreaking 21-20 loss to Scotland in Rome on Saturday, Duncan Weir's last-minute drop-goal condemning them to a third straight defeat.
- 'One step at a time' -
But Ireland coach Joe Schmidt warned the Azzurri, who pushed Wales close before losing 23-15, would be a greater threat because of that narrow reverse.
"We've just got to make sure in the next few weeks we put ourselves in the best position to beat Italy," said Schmidt.
"If you take them any less than 100 percent, you saw what happened to Wales," the New Zealander, in his first Six Nations as Ireland coach, added.
"They will be devastated by the loss against Scotland, and that makes them that much more formidable.
"It's one step at a time and unfortunately we tripped up (against England)."
Mike Brown, the England full-back, was named man-of-the-match after starring in both defence an attack.
"Mike Brown's goalkeeper save when there was no one behind him in the first half after our kick on, that was probably the defensive highlight, even without anyone having to make a tackle," said an admiring Schmidt.
"And then his running in broken field was maybe the difference between the two teams," the former Leinster boss explained.
Schmidt added: "Three points, that's ultimately the fine margin that existed.
"We felt we searched pretty long and hard for that three in the last 10 minutes of the match and we didn't quite get there."