Tries from Danny Care and Luther Burrell, as well as 19 points from the impressive Owen Farrell, saw England chalk up a 29-18 victory over Wales - a first against the Red Dragons under Lancaster.
Victory put England in second place, although their points difference is 49 behind Ireland and should Joe Schmidt's men beat France in Paris in the final game of the 2014 RBS 6 Nations, the title will be theirs unless Lancaster's side rack up a cricket score against Italy in Rome.
And Lancaster acknowledged that all they can do is focus on defeating Italy, before turning their attentions to Paris where a France win would almost certainly hand England the title.
France can still win the title but their points difference is vastly inferior to England and they will need either an Italian win, or a thumping victory over Ireland.
But with so much still undecided, Lancaster is far keeping his cards close to his chest.
"All we can do is control the controllables. Italy will be disappointed and they will be back at home in front of their passionate home fans and it will be a tough match," he said.
Instead, Lancaster preferred to revel in a first ever win over Wales since he took over but he remains adamant the result will have little bearing on the two side's World 2015 pool fixture - the next time Warren Gatland brings his side to Twickenham.
"I'm really proud. We showed our attacking intent from the start but in the first half we kept on getting punished by Leigh Halfpenny for our ill-discipline," he added.
"We have got a big game next week now, we're still in the fold.
"They got one over us last year and that was in the back of our minds but I said last year, it will be a different day [during the World Cup]. But this is our day and we'll enjoy the occasion."