Francisco Cerundolo's love affair with the Miami Open showed no signs of cooling after the World No. 19 from Argentina stunned Russia's Daniil Medvedev 6-0, 4-6, 7-5 on Monday to reach ​the round of 16.

The 27-year-old clinched his first Top-10 victory of the ‌season by vanquishing the former World No. 1, who arrived in Florida in peak form after thwarting Carlos Alcaraz's 16-0 start to the season, en route to a runner-up finish at Indian Wells.

"I felt good in my first round match ​here, and now I feel way better," Cerundolo said. "I'm recovering that confidence. The ​level was there, I was just trying to find it. But now, (I ⁠am in) the round of 16, so hopefully I can keep it up."

The match began ​with Cerundolo racing through the opening set, but Medvedev rallied from 3-1 down in the second ​set to force a decider.

The two traded high-quality rallies amid the sweltering Florida heat, with Cerundolo's aggressive forehands repeatedly disrupting Medvedev, before the South American produced an instinctive winner to end the two-hour, 17-minute encounter.

"I didn't know what to ​expect ... It was a great match, super tough," Cerundolo added. "It was my first match against ​Daniil. He's probably one of the only guys on Tour who I have never played. He has had ‌a ⁠great year so far, so I didn't expect to be up 6-0 in the first set and a break up in the second."

The defeat ended Medvedev's ​latest bid for a Tour-leading 20th win of the season, with the 30-year-old exiting Miami with a 19-5 record that includes titles in Brisbane and Dubai.

On the women's side at the Miami Open, World No. 1 and defending champion Aryna Sabalenka of Belarus battled past China's Zheng Qinwen 6-3, 6-4 to reach the quarterfinals.

Zheng was making her third appearance in the last 16 in Miami after knocking out two Grand Slam winners from the host country: American pair Sloane Stephens and Madison Keys.

Sabalenka broke Zheng twice in the first set to build a 5-1 lead. Although the Chinese competitor broke back in the seventh game and then held in the eighth, she failed to stop her opponent from wrapping up the set in nine games.

The Belarusian broke Zheng first again in the third game of the second set, before rejecting the 23rd seed's love game break attempt in the eighth and holding in the 10th to seal the deal.

After bagging her eighth win over Zheng in nine matches, Sabalenka will meet the USA's Hailey Baptiste in the last eight.