Daniil Medvedev's drought against nemesis Roberto Bautista Agut continued after the Miami Open top seed crashed out in the quarter-finals.

Medvedev had never beaten Bautista Agut prior to Wednesday's showdown – the world number two upstaged in the 2017 Maharashtra Open final and last year's Western & Southern Open quarter-final.

The Russian star was once again unable to solve the Bautista Agut riddle, upstaged 6-4 6-2 at the ATP 1000 tournament midweek.

Bautista Agut – the seventh seed and oldest player remaining in the draw – broke for a 5-4 lead in the opening set and never looked back against the 2021 Australian Open runner-up.

You cannot pass this wall @BautistaAgut is rock solid tonight at the #MiamiOpen pic.twitter.com/wtjWkNTDb3
— ATP Tour (@atptour) April 1, 2021

The only player in the last eight to have reached the quarter-final stage previously, Bautista Agut continued where he left off in the second, making Medvedev uncomfortable as he booked a spot in the semi-finals.

Spanish veteran Bautista Agut will face Jannik Sinner in the semi-finals of the Miami Open.

Italian sensation Sinner proved too good for Alexander Bublik 7-6 (7-5) 6-4 in the day's early match.

Sinner, 19, became just the eighth teenager to reach the semi-finals in the tournament's history – five of those men have gone on to top the ATP rankings, Andre Agassi (1990), Lleyton Hewitt (2000), Rafael Nadal (2005), Novak Djokovic (2007) and Andy Murray (2007).

"You're not a human! You're 15 years old and you play like this."

It's all respect between Alexander Bublik & @janniksin

: @TennisTV | #MiamiOpen pic.twitter.com/negacVxNMP
— ATP Tour (@atptour) March 31, 2021

Sinner drew high praise from a stunned Bublik post-match in Miami.

"He's not [human]. That's a fact," said Bublik. "I asked him if he's a human or not, because for me, it's very surprising that the guy at his age has this mental toughness that many, many other players don't have.

"I called him a robot a couple of times during the match, but I do it in a very sincere way because he's a really, really a great player."