Table toppers PSV Eindhoven and AZ Alkmaar both suffered heavy defeats on Sunday.
Leaders PSV played in the early kick-off at Groningen and they went down 3-0 at the Euroborg.
The hero for the home side was Korean Hyun Jun-suk who grabbed a brace, sandwiching an effort from Leandro Bacuna.
PSV's defeat meant AZ could have gone top with just a point from their trip to Utrecht, but they suffered the same margin of defeat.
Alexander Gerndt struck twice before the break, and Utrecht were in an even better position ahead of half-time as they added a third through Edouard Duplan.
Ajax closed the gap to the leaders as they eased to a comfortable 4-1 win over NEC Nijmegen.
The Amsterdam giants were 3-0 up by the interval with Dmitri Bulykin scoring twice and Jan Vertonghen also on target.
Siem de Jong added another on the hour before NEC claimed a consolation through Rens van Eijden.
Finally, Twente - like Ajax - kept up the pace with the top end as they clinched a 4-1 win at seventh placed Vitesse Arnhem.
Steve McClaren's side were ahead after just six minutes through Leroy Fer but they had to wait another hour for their second.
Luuk de Jong doubled their lead, before strikers from Ola John and Nacer Chadli sealed the win.
Vitesse also won a late penalty with Peter Wisgerhof sent off for Twente, but Wilfried Bony could not convert although they did grab a consolation with Mike Havenaar scoring.