John Millman has been sent crashing out of the Monte Carlo Masters after going down in his first round clash 3-6, 6-1, 6-1 to world No.18 Roberto Bautista Agut.
Millman, in his first match on clay this year, took the opening set after breaking the rugged Spaniard twice and saving four break points.
However Bautista Agut hit back emphatically in the second set, breaking the Australian No.3's serve three times before doing so twice again in the decider to set up a clash with world No.2 and 12-time winner Rafael Nadal.
Belgium world No.21 David Goffin moved to the second round with a comfortable 6-1, 6-4 win over Guido Andreozzi on a day when most of the other main names also made it through unscathed.
Goffin, who defeated Dominic Thiem and Novak Djokovic to progress to the semi-final in 2017, was largely error-free and able to save five of six break points to secure his place in the next round.
He will face Dusan Lajovic in the second round, after the Serb earlier defeated Malek Jaziri of Tunisia 6-4, 6-4.
Victory then would set up the possibility of a third-round showdown with Thiem.
The biggest surprise of the day was the exit of world No.15 Denis Shapovalov, who lost 5-7, 6-3, 6-1 to wily German Jan-Lennard Struff.
The 20-year-old Shapovalov arrived after a good run on hard courts at the Miami Open, where he lost to Roger Federer in the semi-finals.
Fabio Fognini survived an early scare in his first round match with qualifier Andrey Rublev, which ended 4-6, 7-5, 6-4.
Top seed Novak Djokovic faces the unseeded Philipp Kohlschreiber in the second round on Tuesday with Australia's Alex Popyrin also in action against veteran Frenchman Gilles Simon.