Retiring Spaniard David Ferrer set up a meeting with Rafael Nadal at the Barcelona Open, where Monte Carlo Masters champion Fabio Fognini was ruled out with injury.
Ferrer turned 37 this month and will call time on his tennis career following May's Madrid Open, but he will do so having faced compatriot and clay king Nadal at least one more time.
The former world number three defeated Mischa Zverev 6-3 6-1 on Tuesday and then upset Lucas Pouille by the same scoreline 24 hours later.
That was enough to secure a last-16 clash against 11-time champion Nadal, who saw off Leonardo Mayer 6-7 (7-9) 6-4 6-2.
Nadal has known his fair share of injury problems in the past 12 months, but it was Fognini, his conqueror last week in Monaco, who suffered on Wednesday.
A hamstring issue saw the Italian withdraw, with Roberto Carballes Baena beating Nicola Kuhn in three sets in his absence.
Guido Pella and Cristian Garin have both proved dangerous opponents on clay this year, with that trend continuing in Spain.
Pella, who led Nadal before falling short in the Monte Carlo quarter-finals, came through in two sets against sixth seed Karen Khachanov on Pista Manuel Orantes.
Then Garin, in the final match of the day, blew away Canadian star Denis Shapovalov 7-5 6-2.
Daniil Medvedev, Grigor Dimitrov, Benoit Paire, Felix Auger-Aliassime and Mackenzie McDonald all registered victories, too.
At the Hungarian Open, last year's finalist John Millman - the sixth seed this year - was upset 6-4 2-6 6-2 by Attila Balazs in the round of 16.
There were wins elsewhere for Pierre-Hugues Herbert, Pablo Cuevas and 17-year-old Jannik Sinner in Budapest.