The Dutch side were just seconds away from the Champions League final this week after leading Tottenham 3-2 on aggregate deep into injury time at the Johan Cruyff Arena.
But with what was almost the last kick of the game, Lucas Moura completed his hat-trick to seal a famous comeback for the visitors, who progressed on away goals having trailed 3-0 and now meet Liverpool in the decider.
That incredible reversal of fortunes, however, did not seem to weigh heavy on Erik ten Hag's side as they breezed past Utrecht.
The visitors briefly threatened to cause an upset in Amsterdam when Othman Boussaid handed them the lead in the first minute.
From there though it was all Ajax, with Klaas Jan Huntelaar restoring parity after 14 minutes before Donny van der Beek gave his side the advantage on the stroke of half time.
A Dusan Tadic double after the break put the result beyond doubt and left Ajax on the verge of reclaiming the title from reigning champions PSV.
PSV, the only side still mathematically able to catch their rivals in the race, were downed 1-0 by AZ to slip three points behind the leaders.
Ajax also enjoy a healthy advantage on goal difference, meaning that only an improbable sequence of results in Wednesday's final round of fixtures will stop them taking the crown.
A win or draw away to De Graafschap will be enough to secure the title for Ten Hag's charges, while PSV need to win to have any chance of retaining the Eredivisie.
Even if the Eindhoven team do prevail Heracles, they will also require De Graafschap to triumph and for the two games to yield a goal difference swing of 15 in their favour.
Ajax last won the Eredivisie in 2013-14, with PSV taking three titles and Feyenoord one in the last four seasons.
They remain Netherlands' most successful club in history, with 33 title wins to date compared to 24 for PSV.