Denmark's Holger Rune ended Stefanos Tsitsipas' winning run to reach the quarter-finals.
Tsitsipas, seeded eighth, had won his past seven matches taking in a maiden Dubai Tennis Championships title, but was beaten 6-4 6-4 in one hour 33 minutes.
The highlight of the match was a remarkable through-the-legs lob from the baseline by Rune to save break point in the second set.
Having reached the same stage in Indian Wells last year, the 21-year-old is the first Scandinavian since Stefan Edberg in 1994-95 to reach back-to-back quarter-finals.
Rune will play Tallon Griekspoor in the last eight after the Dutchman beat Japanese qualifier Yosuke Watanuki in a rain-affected match 7-6 6-1.
Russian fifth seed Daniil Medvedev set up a quarter-final meeting with France's Arthur Fils by beating American Tommy Paul 6-4 6-0.
British number one Jack Draper plays American third seed Taylor Fritz in the last 16 on Wednesday.