Alcaraz, 19, becomes youngest top-five player since Nadal
Alcaraz is a huge admirer of Nadal, beat him in Madrid and has also trained with the 22-time Grand Slam champion.
Spain rising star Carlos Alcaraz can move ahead of Rafael Nadal as the player with the most ATP Tour titles this season if he wins a fifth final in Hamburg
Alcaraz will become the youngest player in the top five of the ATP rankings since Nadal in 2005 after reaching the Hamburg Open final.
Alcaraz, 19, beat Slovak Alex Molcan 7-6 (7-2) 6-1 and will face Lorenzo Musetti for the title on Sunday.
The Miami Open and Madrid Open champion has won his five previous Tour finals.
"I have a lot of confidence for the final and hope to make it six-for-six," said Alcaraz after his latest clay win.
"Lorenzo is playing really well. It's going to be a great final."
Nadal was under a month away from turning 19 when he became fifth in the world for the first time.
Alcaraz is a huge admirer of Nadal, beat him in Madrid and has also trained with the 22-time Grand Slam champion.
He will overtake Norwegian Casper Ruud when the updated rankings are released on Monday.
Musetti, 20, reached his first Tour final with a 6-3 7-6 (7-3) victory over Francisco Cerundolo.
The world number 62 said he was surprised by the form that has earned him a meeting with the top seed in Hamburg, following his first-round exit at the Swedish Open.
"I was not playing my best tennis last week," said Musetti. "I didn't expect to be in the final here."
World number 81 Bernarda Pera won her second title in seven days by beating top seed Anett Kontaveit 6-2 6-4 to claim the women's singles title in Hamburg.
After tasting WTA Tour glory for the first time in Budapest last week, Pera earned a 12th consecutive win to stun the Estonian world number two.
American Pera won her 24th straight set to clinch victory and is expected to enter the top 60 in the rankings, having been world number 130 when she arrived in Budapest
