Centre Jonathan Joseph scored two superb tries as England recovered from a stuttering start to hammer Italy 47-17 at Twickenham to make it two wins out of two in the Six Nations championship, and remain on course for their first title since 2011.
Ireland beat France 18-11 in Dublin to join England at the top of the table, with the leaders to face a crunch match against each other next weekend.
England scored six tries and their backline showed some real pace and panache but they were looked shaky in defence at times as Italy started and finished strongly.
"At half-time we gave them a rev up, we said we needed to up the intensity, and I think we did that in the second half," England coach Stuart Lancaster says. "I'm slightly disappointed that we didn't do a bit better but I'm really pleased for Jonathan Joseph. He's having a great season so far and I'm delighted for him."
It was a very different atmosphere at Twickenham to the bearpit of Cardiff last week when England impressively beat Wales but home fans expecting a repeat of last year's 52-11 Roman stroll were given a rude awakening as Italy captain Sergio Parisse scored the opening try after two minutes.
After a backline shuffle caused by an early injury to fullback Mike Brown, England eventually settled and, after a penalty from first-five George Ford, went ahead after 24 minutes when loose forward Billy Vunipola got the benefit of a tight TMO call.
Joseph, who made such an impression against Wales last week, again showed the combination of speed and step that has been shredding Premiership defences all season to score a scintillating second after captain Chris Robshaw, yet again, had forced a halfway line turnover.
Ford landed another penalty at the start of the second half but Italy looked livelier and were rewarded when centre Luca Morisi burst through for his side's second try.
First-five Kelly Haimona, however, missed his second conversion, having also missed two penalties, as Italy's long-standing goalkicking problem again dogged them.
Then a lack of concentration after a collapsed scrum allowed quick-thinking scrumhalf Ben Youngs to tap and scamper over untouched.
Good work by Ford opened a hole that Joseph, shifted to the wing, roared through for his second before replacement first-five Danny Cipriani came on for his first taste of the Six Nations in seven years and within a minute was scoring a try after Jonny May's pace took him through an impossible gap.
Fellow replacement Nick Easter then became England's oldest-ever tryscorer when the 36-year-old replacement trundled over for England's sixth score but Italy had the last word with a well-taken second for Morisi.
Ireland hung on to beat France to seal their ninth win in a row and make it two victories from two to start the defence of their championship.
Returning first-five Johnny Sexton outkicked opposite number Camille Lopez to give Ireland a six-point half-time advantage that they stretched in the second period before a Romain Taofifenua try meant the hosts had to survive a late onslaught.
"Irish teams don't beat France all that regularly so to do it back to back...is fantastic," captain Paul O'Connell says.