BELGRADE (Reuters) -Novak Djokovic crashed out of his own tournament after Russia's Aslan Karatsev beat him 7-5 4-6 6-4 on Saturday to reach the Serbia Open final and avenge the Australian Open semi-final defeat by the world number one.

Djokovic suffered his second successive shock exit on red clay in quick succession after he was beaten by Briton Dan Evans in the third round of the Monte Carlo Masters last week, having failed to convert a barrage of break points against Karatsev.

The Russian will meet Matteo Berrettini in Sunday's final after the Italian beat Japanese rival Taro Daniel 6-1 6-7(5) 6-0 in the other semi-final at Djokovic's tennis centre by the Danube river in Belgrade.

Djokovic praised Karatsev after what he said was a forgettable evening.

"Hats off to Karatsev, he was bold and deserved to win," Djokovic told an online news conference.

"I will probably not be able to recollect all the memorable rallies in this match because I lost. I am not happy with my performance, I put up a fight but he delivered great shots every time he needed to.

"I was unlucky at times, it all came down to one or two shots but I had too many ups and downs throughout the match."

Karatsev said: "This is definitely the most important victory of my career. At the Australian Open in Melbourne I felt like I was playing against a wall but this is a different surface and I was focused."

(Writing by Zoran Milosavljevic; Editing by Christian Radnedge and Clare Fallon)