The Belgian champions were on a run of five games unbeaten, including two wins in the league and a hard-fought draw at home to Napoli, before their trip to title contenders Standard.
Felice Mazzu made two changes to the side that beat Royal Excel Mouscron in their last outing, with Sebastien Dewaest and Bryan Heynen coming in to replace Carlos Cuesta and Patrik Hrosovsky.
The core of Genk’s first-choice lineup for the campaign so far, therefore, was retained, including top scorer Mbwana Samatta (six goals) and key creator Junya Ito (seven assists).
But while the visitors enjoyed the better chances for much of an end-to-end game—which saw Standard manager Michel Preud’homme yellow-carded and assistant Eric Deflandre sent off—it was ultimately decided by the hosts.
Standard’s winner came via Samuel Bastien, whose long-range strike evaded Gaetan Coucke to give Genk their fourth league loss of the season.
Mazzu sent on wildcard Paul Onuachu—who prior to Saturday had scored five goals in seven appearances, including two as a substitute—in response, but it came too late for Genk.
They cannot be underestimated on Wednesday night, however, with Genk having lost just once at home so far this season, winning five and drawing one.
That draw was the aforementioned stalemate against Napoli, in which Mazzu’s side weathered the storm of their Serie A opponents and produced some promising chances of their own.
Genk lost midfielder Ianis Hagi on the hour mark on Saturday, but it remains to be seen whether the 20-year-old son of Romanian legend Gheorghe Hagi will be absent in midweek and Mazzu is facing few other injury concerns.