Qualifier Daniel Altmaier delivered a surprise straight-set victory over seventh seed Matteo Berrettini to reach the French Open fourth round.
The 22-year-old beat the Italian 6-2 7-6 (7-5) 6-4 in Paris.
It was a composed display from the German world number 186, who is yet to drop a set during his first appearance in the main draw of a Grand Slam.
He joins Sebastian Korda in the last 16 as the first qualifiers to reach that stage at Roland Garros in nine years.
Altmaier will now face 17th seed Pablo Carreno Busta in the last 16.
The US Open semi-finalist was the winner of an all-Spanish meeting with 10th seed Roberto Bautista Agut, seeing off his compatriot 6-4 6-3 5-7 6-4.
Carreno Busta, who was a break down in the fourth set, hit 65 winners to make it through in three hours and 22 minutes.
Greek fifth seed Stefanos Tsitsipas, 22, was racing into the next round when Slovenian opponent Aljaz Bedene was forced to retire at 6-1 6-2 3-1 with an ankle problem.
Tsitsipas will play Grigor Dimitrov or Roberto Carballes Baena next.
Russian 13th seed Andrey Rublev breezed past Kevin Anderson to reach the fourth round at Roland Garros for the first time.
Rublev hit 27 winners and did not face a single break point as he dominated the South African to win 6-3 6-2 6-3.
The 22-year-old, who had never won a French Open match before this week, will play Marton Fucsovics for a place in the quarter-finals.
Hungarian Fucsovics beat Brazil’s Thiago Monteiro 7-5 6-1 6-3.