With Simona Halep and Caroline Wozniacki, the world No 1 & 2, joining Serena Williams in crashing out across the opening days of the tournament the path has opened up for British No 1 Konta in Florida.
Having started with a routine win over another Belgian, Kirsten Flipkens, in the second round, it was more of the same from Konta as she recovered from being broken early on to dominate and book her place in the fourth round in just over an hour.
The 26-year-old has endured a tough season having not gone beyond the last 16 of any tournament and if she is to do so at Crandon Park she will need to beat 37-year-old Venus Williams to reach the quarter-finals.
Konta beat Williams in the semi-final on her way to the title last year, before toppling Wozniacki to lift the trophy - her last tournament victory - and Williams had to save three match points on her way to a three-set victory over Kiki Bertens
World No 8 Williams, three times a champion in Miami, needed almost three hours before seeing off the 27th seed 5-7, 6-3, 7-5 - Bertens coming from 5-0 down in the opening set to reel off seven games in succession.
As for Konta's match, the pair traded early breaks before Konta was handed the initiative and a second break when 21-year-old Mertens doubled-faulted four times in the same game to give Konta a 3-2 lead.
From that position Konta went on to lose just one of the next 10 games capitalising on an error-strewn display from her opponent to go through the gears and showcase her own big serve and baseline winners.
Konta consolidated her break and was handed two more break points in the seventh game which she took with a fine two-handed backhand winner before serving out the set with the minimum of fuss.
She then motored through the second set, securing a 4-1 advantage by breaking to love and having seen one set point go begging on the Mertens serve, she took the next opportunity to come her way.
Puerto Rico's Monica Puig, the 2016 Olympic gold medalist, also reached the fourth round, following up her upset of second seed Wozniacki with a 6-3, 7-5 victory over Greece's Maria Sakkari.