Mertens, seeded 25th, followed her shock third-round win over second seed Elena Rybakina with another commanding performance at the grass-court Grand Slam.
She is finally into the last eight at the All England Club at the ninth attempt.
The 30-year-old's only Grand Slam semi-final appearance came at the 2018 Australian Open.
Mertens, a two-time Wimbledon doubles winner, faces Czech ninth seed Linda Noskova or 2025 Australian Open champion Madison Keys in the quarter-finals.
Wimbledon 2026
Wimbledon is taking place from June 29th to July 12th at the All England Club in south-west London. With 128 players in the draw, it is the third of the four Grand Slams of the tennis season and the only one played on grass.
Men's singles draw and results | Women's singles draw and results | All you need to know about the tournament | Find all our Wimbledon coverage here