Verdasco delivered the upset of the tournament when he defeated the in-form Dominic Thiem 4-6, 6-4, 7-5 in a display of sustained power and precision.
The going did not get any easier for Verdasco as he had to then square off against Khachanov. However, the Spaniard once again showed grit and determination to pull off a stunning victory.
On the other hand, Rafael Nadal breezed past both of his opponents, defeating both Jeremy Chardy and Nikoloz Basilashvili in straight sets. Nadal showcased true clay court dominance and will now be pumped up for his quarter-final match against his compatriot.
Nadal and Verdasco have met 19 times in the past, with the former leading their head to head 16-3. However, tonight's clash will be their first meeting in over two years. The last time they crossed paths was in the second round of Indian Wells in 2017, a match which Nadal won 6-3, 7-5.
Both players will know each other's weaknesses and will look to exploit them to the best of their abilities. Nadal will obviously have the edge physically, having spent a lot less time on court.
If Verdasco is to have any chance of pulling off an upset, his forehand needs to fire on all cylinders. That's the only weapon that can truly trouble Nadal.
However, Nadal is eyeing his first clay-court title of the season and seems to be in top form. He has blown away all of his opponents thus far and it's very unlikely that he drops a set, much less loses the match to Verdasco.
Probability of winning: Rafael Nadal - 90%, Fernando Verdasco - 10%