Top seed Carlos Alcaraz dominated Gael Monfils 6-2 6-4 and fourth seed Alexander Zverev escaped a tight first set en route to a 7-6(4) 6-3 win over Christopher Eubanks to reach the last 16 at the Miami Open on Monday.
Alcaraz is on a quest to capture the Sunshine Double after his triumph at Indian Wells and the 20-year-old was never really threatened in a match-up of two of the game's most entertaining players.
The Spaniard appeared to be cruising to the finish line when he served for the match leading 5-2 but Monfils rifled a forehand winner to break and extend the match.
The comeback would prove short lived, however, with Alcaraz deploying a textbook serve and volley on his first match point to seal the win with a love hold.
Alcaraz, who won the tournament in 2022, will next face Italy's Lorenzo Musetti, who beat American Ben Shelton 6-4 7-6(5).
Zverev limited his unforced errors, converted his two break point opportunities and saved four of the five break points he faced before closing out the one hour and 44-minute contest with a forehand volley into the open court.
Eubanks had a chance to serve out the first set at 5-3 but was denied by Zverev, who broke the American again early in the second set to build a 3-0 lead. Zverev later had to save three break points to serve out the match.
Awaiting Zverev in the last 16 will be 15th seed Khachanov, who converted his fifth match point to secure a 6-1 5-7 7-6(5) win over Argentine 20th seed Francisco Cerundolo. Zverev has a 3-2 record against Khachanov and won their most recent meeting in the gold medal match at the Tokyo Olympics.
Bulgarian Grigor Dimitrov, Poland's Hubert Hurkacz, Australia's Alex de Minaur and Hungarian Fabian Marozsan also all advanced.
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