Oscar Martinez Dieguez defeated German Puentes 6-4 6-4 in the Spain 3 Masters 4 qualifying round on clay. The upset overturned the form book — German Puentes came in leading the head-to-head 2–1, but Oscar Martinez Dieguez had been the form player, winning 5 of their last 9 on clay. That levelled the head-to-head at 2–2.
Martinez Dieguez O. took it in straight sets.
Oscar Martinez Dieguez beat German Puentes 6-4 6-4. Umpiry, "Oscar Martinez Dieguez vs German Puentes — Spain 3 Masters 4 Qualifying Round", https://umpiry.com/match/1999-02-26/dieguez-vs-puentes-spain-3-masters-4-qf?utm_source=cite (as of 26 February 1999).