American Venus, seeded 10th and competing in her 20th French Open, powered 22 winners and converted six of 13 break points as she picked apart the 60th-ranked Belgian in just over an hour.
Momentum appears to be building for Venus as she attempts to win a title she came closest to lifting in 2002, when she was beaten in the final by her younger sister Serena.
Venus, a seven-times Grand Slam singles champion who turns 37 this month, will play Switzerland’s Timea Bacsinszky for a place in the quarter-finals.
Meanwhile, reigning women’s champion Garbine Muguruza gained further momentum in the defence of her title with a 7-5, 6-2 win over Kazakh 27th seed Yulia Putintseva.
The Spaniard closed out victory with an ace in a match that featured 11 breaks of serve in 20 games played.
“I think the more matches I play and the toughest victories I think gives you self-confidence, successful feeling out there,” said Muguruza.
“I think it’s important with all the three matches that I played that are not easy at all.”
Muguruza plays French 13th seed Kristina Mladenovic, who rallied from 5-2 down in the third set to beat American Shelby Rogers, for a place in the last eight.
“I have no words to describe the love I have for you,” said Mladenovic, who rallied from 5-2 down in the third set to book a clash with defending champion Garbine Muguruza on Monday.
“Honestly, I went through so many emotions during this match that I don’t know what to say. Your support helps me so much. I had goose bumps.”
“Kiki! Kiki!,” the crowd chanted again in an electric atmosphere, declaring their love back to Mladenovic.
One of the favourites after reaching the final in the Madrid and Stuttgart claycourt tournaments, the 13th-seeded Mladenovic is looking to become the first French woman since Mary Pierce in 2000 to lift the Suzanne Lenglen Cup.
After easing past former runner-up Sara Errani in the previous round, Mladenovic knew Rogers had the weapons to bother her, the American having won their only meeting 6-1 6-1 on a hard court.
Clay made a difference as Mladenovic had more time to run around and use her devastating forehand but, having been hampered by back problems since day one, she was shaky on serve - delivering 13 double faults and winning 42 percent of her points on second serve.
“Physically I’m very confident. I could have run for another hour,” said Mladenovic.
Australian 23rd Samantha Stosur, the 2010 French Open runner-up, breezed into the fourth round with a 6-2, 6-2 rout of American qualifier Bethanie Mattek-Sands.