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 took place from June 29th to July 12th at the All England Club in south-west London. It is the third of the four Grand Slams in the tennis season, and the only one played on grass.
Men's singles draw and results | Women's singles draw and results | Find all our Wimbledon content here