MADRID, Spain (AFP) — Defending champion Carlos Alcaraz celebrated his 20th birthday on Friday by reaching the Madrid Open final, likening himself to "a bull" in his straight sets win over Borna Coric.

The world No. 2 was at his best to defeat the Croatian 6-4, 6-3.

He will face Germany's Jan-Lennard Struff, the world No. 65, who had originally been knocked out in qualifying before winning a reprieve, in Sunday's final.

Alcaraz said he called upon some of the inner motivation which helped him triumph at the US Open in New York last year when he captured his maiden Grand Slam crown.

"There was a moment when I repeated what I repeated at the US Open, that I'm a bull, and that I could do it, and it helped me," he explained.

Alcaraz, reaching his fourth Masters 1000 final, broke for a 3-2 lead in a tight first set and served it out.

He broke for 2-1 in the second set and after world No. 20 Coric immediately hit back, did so again for a 3-2 lead, which he consolidated.

Alcaraz sealed the match with another break when Coric went long, ensuring he reached the final only dropping one set en route, against Emil Ruusuvuori.

The top seed was able to celebrate with a birthday cake, offered to him by the tournament organizers after his victory.

The only dampener for Alcaraz was news that Spanish compatriot and 22-time major winner Rafael Nadal would miss next week's Italian Open through injury.

Nadal hasn't played since the Australian Open in January due to a hip injury and is now a serious doubt for the French Open in three weeks' time and where the 36-year-old has been champion on 14 occasions.

"I hope to see him at Roland Garros 100 percent. The world wants to see him at 100 percent," Alcaraz said.

Struff, 33, made only his second career final by defeating Russia's Aslan Karatsev who had beaten him in qualifying last weekend.