Feyenoord held a one-point lead over third-placed NEC ahead of this weekend's 31st round of the Dutch Eredivisie, but struggled in recent weeks with their last league win dating from March 15th (2-1 against Excelsior).
With Gernot Trauner back in the starting XI for the first time in over a year, Aussie left-back Jordan Bos broke the deadlock early with a deadly strike, coolly firing a lay-off from Luciano Valente in Etienne Vaessen's top right corner after 11 minutes.
Bos played a big role up front again not much later, with the left-back being brought down by Vaessen and earning his side a penalty in the 21st minute. Eredivisie top scorer Ayase Ueda stepped up and fired it in the left corner to double Feyenoord's lead.
After FC Groningen created a small handful of chances late in the opening half, Ueda came closest to expanding the lead shortly after half-time, but could not finish his chance from the counter.
The Japanese hitman struck again nonetheless, turning away perfectly from Tijmen Blokzijl and calmly tucking the ball in the bottom corner to effectively put the game to bed with over 20 minutes remaining.
It became a special day in Feyenoord history and the history of Ilai Grootfaam, who became Feyenoord's youngest-ever player to feature in an Eredivisie game at 16 years and 41 days old.
Thom van Bergen - the player with the most shots in the Eredivisie this season - added the only Groningen goal to a resounding Feyenoord win, tapping the ball into Wellenreuther's goal after Dies Janse picked it off deep in Feyenoord territory.
Raheem Sterling, who's set to leave Feyenoord after the expiry of his contract in June, tried and failed to score his maiden Feyenoord goal in the final minutes, keeping the score at 3-1.
With three rounds remaining, Feyenoord are still in the driver's seat in the race for the second and final ticket to the League Phase of next year's UEFA Champions League, temporarily leading NEC by 4 points ahead of the Nijmegen side's meeting with FC Twente later on Saturday.