Andy Farrell's Ireland had everything going for them heading to Twickerham on Sunday. Apart from missing Garry Ringrose and then the late loss of Iain Henderson, Ireland still looked in rude good health.
Further buoyed by a pep talk by Bono and coming off a confident win against Wales, most were optimistic. England, on the other hand, looked a little wobbly.
They had already seen their Under-20 side walloped by an Irish team that played the game the way it should be played on Friday night and their enigmatic coach Eddie Jones had made a few dubious selections, persisting with Joe Marler at prop, Tom Curry at No 8 and pushing Jonathan Joseph to the wing.
Jones was vindicated and England were well worth their impressive win, bristling with aggression in attack and defence and completely outplaying Ireland in most aspects of the game.
At 17-0 down at halftime, you just could not see a comeback. Maybe it was time to ring the changes, and let some of the bench players show what they could do.
The question was whether or not Irish coach Andy Farrell would risk replacing some household names in an effort to bring something positive back to Ireland's play. He did – but it was too late to arrest the slide.
Ireland needed to start well but they didn't. In fact, England made the perfect start and really should have scored after just three minutes, only for a try-saving tackle by Irish winger Andrew Conway.
Ireland had seen off their first challenge but not for long. Minutes later England, with all the play at that stage, managed to score a try more from luck than fabrication.
A horrible bounce of the ball went English outhalf George Ford's way rather than Johnny Sexton's.
Worse was to follow. Sexton, mentally shook after the try, missed a bread and butter penalty that would have kept Ireland in touch, despite huge pressure from a rampant English side.
Then England struck again, when another Ford dink in behind enemy lines saw Elliot Daly in.
Irish winger Jacob Stockdale, despite another bobbling ball, really should have made himself larger in covering the ball. Arms outstretched by Stockdale would at least have made it harder for Daly to see a way through.
Ireland suddenly found themselves two scores down, with little chance of coming back against a team that were simply destroying them.
Ireland were in over their heads at that stage, and struggling to win any battles, even in the set peice.
Given that 17-0 at the break was a mountain to climb against any team, especially away from home, Andy Farrell really had to make changes in the second half to have any chance of pulling something out of this match.
Ireland did at least start positively in the second half with a well-taken try by centre Robbie Henshaw, a boost that gave the massive Irish support something to cheer about.
But in the end, England just had too much power for Ireland.
Ireland lost most of the match-ups, the scrums, the back-row collisions and the back play.
The only area where Ireland gained any parity was the lineout, where the team more or less held its own.
It was a serious wake-up call. Of course, Ireland still have a lot to play for in the Championship, given that their next game is a probable home win against Italy.
But it will also be a reality check – Ireland need to improve again to dine at rugby's top table, and that may require some serious reshuffling before France in Paris.
The question is what does Farrell do for the Italian game?