Spaniard Alcaraz, aged just 20, ended Djokovic's hopes of becoming the first male player since Australian Rod Laver in 1969 to win all four Grand Slams in a calendar year when he won a thrilling five-set final at Wimbledon in July.

However, Djokovic is one match away from a first triumph at the United States Tennis Association Billie Jean King National Tennis Center since 2018 and adding to his 23 career majors.

Standing in his way is Medvedev, the man who beat him on his last appearance at the US Open final which denied him the "golden slam" of all four major titles in 2021.

Alcaraz began the second semi-final on Arthur Ashe Stadium as favourite to set up a repeat of the Wimbledon epic, but it was 2021 winner and third seed Medvedev, the 27-year-old competing as a neutral because of his country's invasion of Ukraine, whose experience prevailed.

Medvedev took the first set with a 7-3 win in a tiebreak, and took control with a commanding 6-1 victory in the second.

Alcaraz replied by winning the third set 6-3, but Medvedev held firm in the final set to progress to his fifth Grand Slam final.

He had to save three break points at 5-3 in the fourth set, and converted his fourth match point.

Medvedev said afterwards he "played 12 out of 10" to get the better of Alcaraz.

Although a three-time winner, the US Open has not brought the happiest of recent memories for Djokovic.

He has lost six finals at the last major of the year, was disqualified in the fourth round for accidentally striking a line official with a ball not in play in 2020 and missed last year's tournament due to a refusal to get vaccinated against COVID-19.

The 20-year-old Shelton has enjoyed a fairytale run at his home Grand Slam, but Djokovic proved too strong on Arthur Ashe Stadium and triumphed in straight sets in two hours and 42 minutes.

Djokovic took the first set 6-3 and stormed to the second 6-2, but Shelton was able to save match point with his opponent on serve at 6-5 in the third to force a tiebreak.

The 36-year-old made no mistake on his second match point opportunity, which sealed victory in the tiebreak 7-4.

"These are the kinds of matches and occasions that I still thrive on and get me going and inspire me every day to try and work as hard as the young guys," Djokovic said.

"The Grand Slams are the ones that motivate me the most to play my best tennis, perform my best tennis.

"I knew prior to the quarter-finals that I would play an American player and that is never easy.

"To control the nerves and be composed in the moments that matter.

"Today things were going really smoothly for me and then he broke back and it was anyone's game at the end of the third set.

"This is the kind of atmosphere we all like to play in, so I am really, really pleased with this win today."

A Russian player competing as a neutral also reached the women's doubles final, Vera Zvonareva and German playing partner Laura Siegemund beating American Jennifer Brady and Brazil's Luisa Stefani 6-4, 6-1.

Their opponents are set to be Gabriela Dabrowski of Canada and Erin Routliffe of New Zealand, who overcame Chinese Taipei's Hsieh Su-wei and China's Wang Xinyu 6-1, 7-6.

Tomorrow at the US Open is set to feature the women's singles final between Belarusian neutral Aryna Sabalenka and home favourite Coco Gauff, and the mixed doubles final between Americans Jessica Pegula and Austin Krajicek and the pairing of Kazakhstan's Anna Danilina and Finland's Harri Heliövaara.