Alex de Minaur is favourite to advance to his second successive decider at the Next Gen ATP Finals after cruising through group play unbeaten.
The Australian No.1 continued his impressive run in Milan this week when he powered past Casper Ruud in straight sets to cruise into the semi-finals and set up a showdown with good friend Frances Tiafoe.
World No.18 de Minuar, who is the tournament's top seed, smashed 23 winners in the 4-1 4-0 4-2 victory, which eliminated his Norwegian opponent from the round-robin event.
"I knew from playing Casper before that he'd dictate any short ball without a purpose," De Minaur said after his win which was clocked at 61 minutes.
"The game plan was to play on my own terms, play aggressively, play different styles of tennis and it sort of worked.
"The goal I had was any half-chance, go up and back myself at the net. I'm glad I was able to execute and worked out today. I'm looking forward to the semi-finals."
The victory ensured Sydneysider de Minuar, 20, who finished runner-up to Stefanos Tsitsipas at last year's tournament, has gone through undefeated 3-0 in round-robin play for the second successive year.
De Minaur will play second-seeded Tiafoe on Friday after the American defeated Mikael Ymer 4-2 4-2 4-2 to secure second spot in his group.
"I wanted to see him in the final but unfortunately it has to be in the semis," Tiafoe said of de Minaur.
"He's a workhorse. He's going to get every ball, keep every rally extremely long and make me beat him.
"I'm ready for the task.
"We're going to go after each other, but we'll still be great friends after."
Serbian Miomir Kecmanovic later secured his semi-final berth with a 4-1 4-1 4-3 (6-4) win over Spaniard Alejandro Davidovich Fokina.
Kecmanovic will face 18-year-old Italian Jannik Sinner, the youngest player in the field, for a spot in the final.