Ajax had a 9-point lead in early April, but that lead dwindled to one point after losing 4-0 to FC Utrecht, drawing 1-1 to Sparta Rotterdam, and conceding a 3-0 loss at home to NEC Nijmegen.
Manager Francesco Farioli changed his approach for the game against FC Groningen by changing his side in four spots. Brian Brobbey, Mika Godts, Kian Fitz-Jim, and Jorthy Mokio got the nod over Wout Weghorst, Steven Berghuis, Player of the Year candidate Davy Klaassen, and Daniele Rugani.
The Amsterdam side showcased their usual defensive rigidity and allowed FC Groningen to create very few chances, mostly restricting the Pride of the North to trying their luck from distance.
The first big chance of the game was for former Chelsea and Aston Villa man Bertrand Traore, who received an accurate deep ball from Jordan Henderson but could not beat Etienne Vaessen with a low strike.
The returned Brian Brobbey proved crucial just before the 30-minute mark as his hold-up play allowed Danish right-back Anton Gaaei to rush up the pitch and fire a thunderbolt towards Vaessen's near post for the opening goal.
Another Ajax goal seemed to be in the making on the brink of half-time, but Mika Godts could not control and direct a header to a colleague in blue. After Groningen's Stije Resink fired a shot over Remko Pasveer's goal one more time before the break, referee Jeroen Manschot brought an end to a foul-riddled first half.
FC Groningen pounced back after half-time when youth international Thom van Bergen profited from Jorrel Hato keeping him onside and craftily slotted the ball past Pasveer for the equaliser.
Ajax struggled out of half-time, prompting Farioli to change his side in four places inside the first twenty minutes.
Two of those changes proved to be crucial as Steven Berghuis, who replaced Bertrand Traore just four minutes before, reached Wout Weghorst, Brian Brobbey's replacement, with a weighted cross into Groningen's box, and the striker just tipped it in for a crucial 2-1.
In-form midfielder Luciano Valente was a handful for the Ajax defence on several occasions and threatened the Amsterdam side once more with a thunderous strike which hit Pasveer's post.
Late drama
A roar came from the away end when Steven Berghuis thought he'd given Ajax a 3-1 lead, but the winger was flagged for offside.
After the six minutes of added time commenced, tensions boiled over when Luciano Valente launched a reckless tackle in a challenge with Jordan Henderson and was sent off with a direct red card.
As a crucial Eredivisie game neared its end, FC Groningen got one last free kick in the 98th minute. Mats Seuntjens' free kick was tipped in by Thijmen Blokzijl, who equalised for the home side in the 100th minute.
Substitute Owen Wijndal came close one last time after a corner, but narrowly missed Vaessen's goal as Ajax officially gave up their 9-point lead and head into the final weekend as the second-placed team. Only a slip-up from PSV away at Sparta Rotterdam will give Ajax a lifeline on Sunday.
View all the match statistics on Flashscore.
