Stefanos Tsitsipas and Nick Kyrgios will meet in a blockbuster Citi Open semi-final after straight-sets wins on Friday.
Tsitsipas, the top seed at the ATP 500 event, ran away with a 7-5 6-0 victory over Frenchman Benoit Paire in their quarter-final.
The Greek star is into his seventh semi-final of the year and is set to rise into the world's top five after his run in Washington.
Tsitsipas' win over Paire was not without some controversy, with the 10th seed unhappy with the 20-year-old needing to change shoes early in the second set.
In what shapes as an entertaining last-four clash, Tsitsipas will face Kyrgios, with the pair having played doubles together in Washington.
Kyrgios' fine run continued with an impressive 6-3 6-3 victory over lucky loser Norbert Gombos.
In the other semi-final, Daniil Medvedev will take on Peter Gojowczyk.
Russian third seed Medvedev got past sixth seed Marin Cilic 6-4 7-6 (9-7) and lucky loser Gojowczyk upset Kyle Edmund 6-3 4-6 6-3.
In the doubles, brothers Andy and Jamie Murray bowed out in the quarter-finals.