Paul Onuachu scored Genk’s only goal in their 1-1 draw against Union Saint-Gilloise in Sunday’s First Division A match.
The lanky centre-forward broke the deadlock at the Cegeka Arena from the penalty spot after 73 minutes of action.
The strike was Onuachu's third league goal of the season after five matches but Deniz Undav secured a point for 10-man Union Saint-Gilloise with his last-minute header.
The result ended Genk's three-game winning streak in the Belgian top-flight which include victories against Kortrijk, OH Leuven and Anderlecht.
Onuachu featured from start to finish while Madagascar's Loice Lapoussin and Morocco's Kandouss played for the visitors.
Nigeria descent Ike Ugbo, who made a goalscoring debut for the Smurfs against Anderlecht just before the international break, was introduced as a 91st-minute substitute for Junya Ito.
At the end of the encounter, Genk coach John van den Brom criticised his team’s performance as they could not take advantage of Jonas Bager's expulsion in the 72nd minute.
"The late equalizer was not necessary,” Van den Brom said, as per Voetbal Nieuws. "We are certainly not playing our best game today.
“But the moment you take the lead around the 70th minute with one man more, you can't play the last fifteen minutes like we did. The fear crept into the team and we went just backwards."
Union Saint-Gilloise are above Genk in the First Division A table with 13 points after seven games while the Smurfs are in fifth spot with 11 points but they have a game in hand.
Onuachu and his Genk teammates will shift their focus to Thursday when they travel to Rapid Vienna for their opening game in the Uefa Europa League. Then after the European encounter, there is another trip to Sint-Truiden for their next league fixture on September 19.