Spain's Carlos Alcaraz bagged the biggest win of his career at the US Open, upsetting world No. 3 Stefanos Tsitsipas of Greece 6-3, 4-6, 7-6(2), 0-6, 7-6(5) in a high-quality contest to become the youngest player to reach the fourth round at a major since 1992.
In a battle of swinging fortunes, the 18-year-old ranked 55th in the world rallied from 2-5 in the third set, saving three sets points and breaking twice to avoid going down two sets to one, before advancing in four hours and six minutes.
Alcaraz is the youngest player to beat a top-3 tival at a major since Michael Chang, 17, defeated world No. 1 Ivan Lendl and world No. 3 Stefan Edberg at the French Open in 1989.
"I think without this crowd I would not have the possibility to win this match," Alcaraz told atptour.com. "I was down at the start of the fourth set, so thank you to the crowd for pushing me through. It is an incredible feeling for me."
Alcaraz, whose previous biggest victory came against then World No. 14 David Goffin of Belgium at the Great Ocean Road Open in February, will next play qualifier Peter Gojowczyk after the German defeated Swede Henri Laaksonen 3-6, 6-3, 6-1, 6-4.
The Juan Carlos Ferrero-coached player is the youngest to reach the fourth round at a major since Ukraine's Andrei Medvedev, 17, at the French Open in 1992 and the youngest in New York since Chang, 17, in 1989. The Spaniard now holds a 2-0 record in fifth-set matches.
"This victory means a lot to me," Alcaraz added. "It is the best match of my career. Beating Stefanos Tsitsipas is a dream come true."
Alcaraz captured his maiden tour-level title in Umag and reached the last four in Winston-Salem.
In a high-quality first set, Alcaraz did not play like an 18-year-old making his debut on the Arthur Ashe Stadium as he showed impressive footwork and confidence to dictate terms on his forehand. The Spaniard struck nine winners and committed just two unforced errors in the first set to move ahead.
In the second set, Alcaraz raced into a 3-0 lead. However, Tsitsipas grew into the match and started to find his rhythm on his groundstrokes, hitting with greater depth to force the world No. 55 into errors as he won five straight games before levelling.
After a tense fifth set that featured just one break point opportunity for Tsitsipas, the vociferous Arthur Ashe crowd was fully behind Alcaraz.
Tsitsipas was aiming to reach the fourth round at the US Open for the first time in his fourth appearance in New York. The Greek, who battled past Andy Murray in five sets in his opening-round victory, reached the semifinals on hard in Toronto and Cincinnati.
Earlier this year, the 23-year-old captured his first ATP Masters 1000 title in Monte Carlo and reached his major maiden final at Roland Garros.