At one point, on lap six, Aerts had a 20-second lead over his Belgian compatriot but Iserbyt dug deep and got back on level terms in a race missing world champion Mathieu van der Poel, attending a training camp with his Dutch team-mates. 

It set up a memorable final lap as they both tried to break each other.

It looked like Aerts had succeeded only for Iserbyt to come back again and get away in the final 500 metres and win by eight seconds. 

It was the fourth World Cup win of the season for Iserbyt, who lost the series lead after he was forced to abandon in Namur in Belgium.

"It was the hardest one to win," Iserbyt told Telenet Play Sports after the race.

"I'm enormously tired now. 

"It was so long and I really didn't think that I would bridge back up to him.

"This was a beautiful course. 

"It's really slippery. 

"That's good for me."

With a lead of 41 points, Aerts, though, remains clear in the overall lead and should clinch a second successive overall victory in Hoogerheide in The Netherlands next Sunday (January 26).

"I still need to take care of it," Aerts told Telenet Play Sports.

"I did a good job for the World Cup. 

"Right now the focus is on the remaining races."

Laurens Sweeck, the newly crowned Belgian champion, finished third.

The Netherlands' Annemarie Worst won the women's race, beating team-mate Carmen Alvarado and the United States' Katie Compton. 

The trio were locked together for most of the closing stages until Worst got away in the home straight to record an important victory.

Worst's victory closes her gap to World Cup leader Alvarado to just five, meaning it's all to race for in next week's final race.