The dormakaba rider broke away on the first climb, opening up a gap between herself and Hill and Ralph.
“I got away up the first drag with a good bunch of guys who rode really good lines through the singletrack,” said De Groot.
De Groot, who won the sixth event of the Trailseeker Series in Cullinan yesterday, added that she really enjoyed the trails.
“The organisers just keep improving the route. The rain helped with the grip,” said De Groot, referring to overnight rain that cooled temperatures and packed down the dust on the tracks.
De Groot, who won bronze at this year’s UCI MTB Marathon World Championships in Switzerland, added that this win was the perfect end to what had been a shortened year for her, but her best season yet.
“It’s been a dream season; I’m riding pain free. Things have gone so smoothly.
“This means everything to me. I haven’t had any of the symptoms again.
“I have my old personality back and am in such a good space,” said the 36-year-old, who has fully recovered from vascular surgery.