Miami Open debutant Emil Ruusuvuori claimed one of the biggest wins of his career, coming back from a set down to knock out third seed Alexander Zverev 1-6 6-3 6-1.
After being crushed in the first set, Ruusuvuori switched tactics in the second, playing with more variety and at the net, which helped him seal a stunning victory.
"I don't even know myself [how I turned this match around]," Ruusuvuori said in his on-court interview.
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"I wasn't feeling very comfortable in the first set and I was making a lot of unforced errors. But slowly in the second I was starting to feel a bit better.
Of course, it's one of the biggest wins in my career so it feels good.
The 21-year-old Finn, ranked 83 in the world, will face Mikael Ymer in the round of 32.
Australian Open quarter-finalist Cameron Norrie knocked out Grigor Dimitrov 7-5 7-5 to grab his second win over a top-20 player this season.
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The 25-year-old told Amazon Prime Video afterwards: "It is a massive win for me and I will take a lot out of it.
"It is huge. He is really good on the hard courts and had a good start to the year.
"It was an absolute battle. He came out fast and set the tone for the match, then I was able to be solid towards the end of the first and toughed him out in the second."
Britain's number one Dan Evans lost to American Frances Tiafoe 6-7 (5-7) 6-3 6-3.
Top seed Daniil Medvedev beat Taiwan's Lu Yen-Hsun 6-2 6-2 in 56 minutes.
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Katie Boulter lost in straight sets to Elise Mertens in the second round 6-4 6-1.
Reigning Australian Open chmapion Naomi Osaka won her 22nd match in a row with a 7-6 (7-3) 6-4 win over Australia's Ajla Tomljanovic.
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Osaka, Barty, Watson begin bid for Olympic tennis glory this weekend