World No 1 Carlos Alcaraz was stunned by Sebastian Korda 6-3 5-7 6-4 in the third round of the Miami Open on Sunday, giving the American the biggest win of his career.
It appeared Korda had blown his chance to beat the Spaniard when he failed to serve out the match in the second set but he maintained his composure, breaking for 5-3 in the third set and claiming the victory with an unreturnable serve on match point.
The 25-year-old from Florida, ranked 36th in the world, mixed up his game nicely, effectively using a serve and volley to notch his first win over a top-ranked player while also benefiting from an uncharacteristically sloppy Alcaraz.
"It feels great, I took the scenic route, that's for sure," Korda said.
"It was a little more stress than I would want but I'm happy with how I played, happy with how I stayed with it.
"I got myself into some nasty situations and I kept going, kept believing and I played really well at the end."
Alcaraz began the year by winning his seventh Grand Slam title with a triumph at the Australian Open and did not suffer his first loss of the season until he fell to Daniil Medvedev in the semi-finals of Indian Wells.
He also exited the Miami Open early last year when he fell to unseeded David Goffin of Belgium in three sets in the second round.
Korda will next play either Karen Khachanov or Martin Landaluce in the round of 16.
Watch the ATP and WTA Tours, live on Your Site or and the , giving Your Site customers access to over 50 per cent more live sport this year at no extra cost.
