Australian tennis young gun Alex de Minaur will face top-seeded Stefanos Tsitsipas in the championship match of the Next Gen Finals after battling past Spaniard Jaume Munar.

The second-seeded De Minaur hasn’t lost a match in the Milan tournament and saved all five break points on his way to a 3-4 (5) 4-1 4-1 3-4 (4) 4-2 semi-final victory on Friday.

De Minaur wasted four successive match points at the end of the fourth set and Munar saved another on his service in the fifth but the 19-year-old booked his place in the final on his sixth opportunity.

He said he didn’t know how he recovered from those match points.

“That’s been one of the things I’ve really worked on, on my attitude to try and keep calm and collected,” de Minaur said.

“All the credit to Jaume. He’s an incredible competitor.”

After a sizzling week in a breakthrough year, in which he’s climbed more than 170 ranking spots since December to No.31, de Minaur said he was just enjoying the moment.

“It’s been an incredible year and I’m just riding this roller-coaster. I couldn’t ask for more right now.”

He said winning the final would be “the cherry on top of an unbelievable season for me”.

His clean sweep of the round robin stage of the tournament for top 21-and-under talent took his season earnings past $US1 million ($A1.4 million).

In the other semi, Tsitsipas, who’s ranked No. 15 in the world, beat 2017 runner-up Andrey Rublev 4-3 (3) 3-4 (5) 4-0 2-4 4-3 (2).

The 20-year-old Tsitsipas, who had medical treatment on his left hand during the fourth set, had dropped only one of 30 service games in the tournament before the semi-final but was broken three times by Rublev.