Raducanu snatched a high-quality opening set, surviving two set points against her as she fought back from 6-4 down in the tie-break to win it 8-6 and draw first blood.
Navarro, US Open semi-finalist last year, responded in fine style to seal a double break on her way to a 5-2 lead in the second set as a tiring Raducanu lost her intensity.
The American easily served out to take the second set 6-2 in 37 minutes and Raducanu, who had appeared close to cramping up, needed ice on her legs before the decider.
The British number two quickly fell 2-0 down in the deciding set after being broken for the fourth time in the match and looked down and out when trailing 3-1.
But she rediscovered her energy and after staving off two more break points to make it 3-2 instead of 4-1, Raducanu then reeled off four straight games to lead 5-3.
Navarro battled back to force the tie-break but Raducanu continued to go for her shots and clinched victory in just under three hours.
Jamie Braidwood21 March 2025 21:08
Raducanu was the underdog against the in-form American but impressively held her nerve to win the opening set, saving two set points to win the tiebreak.
But Navarro took charge in the second set, improving her level as Raducanu began to look heavy on her feet in the Miami heat.
The 22-year-old received treatment for blisters on the soles of both of her feet before the third set and Navarro immediately found the break of serve in the decider.
But from there Raducanu responded, finding the belief to stage a remarkable comeback.
Jamie Braidwood21 March 2025 20:57
After reaching the third round, Raducanu will play either Linda Noskova or McCartney Kessler.
Raducanu has a good chance of reaching the fourth round now – in what would bring a huge ranking jump.
Jamie Braidwood21 March 2025 20:46
“I really have no idea how I won that. I don’t know what just happened. It was a match full of ups and downs.
“Emma is a top opponent. She is top-10 and she reaches so many balls. She made it physical and the conditions were difficult. The atmosphere was incredible – two Emmas on court, everyone was cheering for Emma.
“The body is ok. I felt like my legs stopped working in the second set. It was really hot and there was a lot of friction. I don’t know how I pulled that out.”
Jamie Braidwood21 March 2025 20:37
How on earth did that happen?! Raducanu was struggling at the end of the second set and looked to be beaten at the start of the third.
She was struggling with blisters and trailed, only to turn it around and lead 5-3. Then, it turned again and Navarro served at 6-5, but Raducanu clawed back to force the tiebreak.
The level from Raducanu was excellent. What a rollercoaster!
Jamie Braidwood21 March 2025 20:32
That is a stunning win for Emma Raducanu! She finishes in style! On match point, she thumps the forehand winner crosscourt!
Jamie Braidwood21 March 2025 20:30
Raducanu extends her lead to 5-2 behind a couple of attacking points.
Navarro finds the forehand crosscourt. 5-3.
Jamie Braidwood21 March 2025 20:29
A strong serve from Raducanu down the middle. Navarro floats the return long.
A chance for Raducanu but she overcooks the drive volley! Back on serve. 3-2 to Raducanu.
Jamie Braidwood21 March 2025 20:26
Well played Emma Raducanu. Brave from the 22-year-old to attack Navarro, getting a look at two break points.
And she forces the deciding tiebreak! Incredible.
Jamie Braidwood21 March 2025 20:23
Would you believe it! A double fault from Raducanu and Navarro breaks again. The American will now have the chance to serve for the third round, after Raducanu led 5-3!
Jamie Braidwood21 March 2025 20:17