Heading into Super Saturday already assured of the title, England were looking for a second straight clean sweep, but were instead beaten by Ireland 13-9 at the Aviva Stadium.
"Credit to Ireland. We seemed to back up every error with another error".
"It was a really tough game", Best told ITV Sport in an on-pitch interview.
"Look, ultimately we want to finish with a massive result".
The day after St. Patrick's Day, Joe Schmidt's men stood firm between England and history, preventing them from across the water from winning a Grand Slam. There has been a lot made about this game so there is pressure on from that side for us.
"The next Test we play I'll prepare them better". Farrell's next successful effort from the tee after Ireland were penalised at the maul brought England back to within four points with 14 minutes still to play.
The atmosphere in Donnybrook was, of course, aided greatly by events on the pitch, with Ireland competitive until England showed their class in pulling clear in the closing quarter, with sublime centre Emily Scarratt involved in most of their best moments. We went very close it the right hand corner twice with Earls and Ringrose.
"We are Six Nations champions, back-to-back which is a fantastic achievement", he said.More news: Barack Obama predicts the impossible in the Sweet 16
The Red Rose equalled New Zealand's best-ever tally for successive wins against Scotland and can go one better in Dublin this weekend. There are brilliantly coached and they executed their plans well. "It was only 13-9 at the end of the game and we didn't play well". Ireland played superbly and were too good for us on the day and we weren't good enough.
Johnny Sexton unsurpingly came in for some rough treatment with several late hits on the Ireland out-half. "They put us under unbelievable pressure".
Five years ago they suffered a 24-8 loss to Ireland when 80 minutes away from a Slam and England's side on Saturday contained several survivors from that match, including captain Dylan Hartley.
England may have missed the opportunity to break New Zealand's record for consecutive Test wins, but that's only further fuelled coach Eddie Jones' desire to engineer a crack at the world champions themselves later this year.
As expected, Eddie Jones' side retained their Six Nations Championship by doing what was necessary in the first four rounds of the competition, and now they will have their eyes on finishing another tournament unbeaten.
Peter O'Mahony stepped in and produced a man-of-the-match showing, but Ireland boss Schmidt insisted Heaslip's withdrawal was enforced and not due to a late change of hearts on the tactical front. "Even Don Bradman got a 0 in his last test".
England: M Brown (Harlequins); A Watson (Bath), J Joseph (Bath), O Farrell (Saracens), E Daly (Wasps); G Ford (Bath), B Youngs (Leicester); J Marler (Harlequins) D Hartley (Northampton, capt), D Cole (Leicester), J Launchbury (Wasps), C Lawes (Northampton), M Itoje (Saracens), J Haskell (Wasps), B Vunipola (Saracens).