Norway's Casper Ruud continued his bid to land a first major title - and the world number one ranking - by beating Russia's Karen Khachanov to reach Sunday's US Open final.

American hope Frances Tiafoe plays Spanish third seed Carlos Alcaraz in the second semi-final (00:00 BST).

Alcaraz will beat Ruud to become the world number one if he wins the title.

But Ruud is guaranteed to move to the top of the ATP rankings, replacing Russia's Daniil Medvedev, who lost in the US Open fourth round, if 19-year-old Alcaraz loses to 22nd seed Tiafoe.

Ruud has another chance of landing a first Grand Slam title three months after losing to Spain's Rafael Nadal in the French Open final.

The world number seven, who has won eight of his nine tour titles on clay courts, says he has been "surprised" by his run at the final major tournament of the season.

Ruud's performance at Roland Garros consolidated his reputation as a clay-courter but, having reached the Miami final in April and the Montreal semi-finals last month, he has again shown he has the ability to be successful on the North American hard courts.

Against Khachanov, an edgy start saw both players break for the lead in the first set, but fail to consolidate and immediately allow their opponent to level.

That led to a tie-break in which Ruud clinched the opener by winning a 55-shot rally with a beautiful backhand down the line.

Showing a lack of nerves in such a key moment proved pivotal in the outcome of the match.

Ruud served superbly in the second set, not dropping a point in his service games, and moved into a two-set lead by breaking 27th seed Khachanov twice in quick succession.

Khachanov, who played at a consistently high level to beat Australia's Nick Kyrgios in the quarter-finals, improved in the third set and extended the match when he broke Ruud in the 12th game.

But Ruud quickly regained control. A running forehand winner on break point put him into a 2-1 lead in the fourth set, giving him the momentum to take Khachanov's serve again for 4-1 and then clinically close out victory.