Daniil Medvedev has handed Novak Djokovic his first defeat of the year, beating the world No.1 6-4 6-4 to reach the Dubai Tennis Championships final where he'll play holder and Russian compatriot Andrey Rublev for a third title in as many weeks.

With both players putting their early season win streaks on the line, it was Rotterdam and Doha champion Medvedev who drew first blood on Friday by breaking an error-prone Djokovic twice and closing out the first set with a searing forehand.

Playing in his first tournament since winning the Adelaide and Australian Open titles, Djokovic had hardly put a foot wrong, barring a small scare in his opener against Tomas Machac.

The 35-year-old had his moments and looked the better player after going down 2-5 in the opening set, but he dropped his serve again early in the second after hitting a return long.

It was the opening Medvedev could have only dreamed of in his bid to claim a fifth win over Djokovic in 14 matches, and the Russian pounced for a 4-2 lead after some high-octane tennis.

Former US Open champion Medvedev peeled away further with an ace for a crucial hold and sealed a 13th straight win in his next service game.

"When you play Novak, you just have to play your best and hope he doesn't on the day because when he does, he has 22 grand slams so it's going to be tough and it's not certain you'll win," Medvedev said.

"I'm happy I managed to play at a higher level than him... I stayed composed and I'm really happy to be in the final.

"I was feeling great before this match but feeling a little worse now. Every time you play Novak, it's physically tough. A lot of rallies. It was more humid today and he wasn't happy sweating, I wasn't happy sweating.

"We always have tough battles and I'm looking forward to the next one."

Earlier, Rublev reached the final with a first career victory against Alexander Zverev, closing out a 6-3 7-6 (11-9) win on his sixth match point.

"I was thinking it was going to be a third set," Rublev, who will be gunning for his 13th ATP title on Saturday, said. "I was preparing mentally for it but I somehow saved a set point.

"I had a couple of match points but he played well. At 9-9, I made a good return and said, 'OK, let's try to make it here'. I won a crazy rally and was lucky," he said.

Rublev has beaten Medvedev the last two times they squared off including at the ATP Finals last November.

That match is better remembered for Rublev's appeal for peace. He wrote "Peace, Peace, Peace, All we need," on a TV camera lens. He made a similar appeal shortly after Russia's invasion of Ukraine just over a year ago.

On Friday, Rublev renewed that message.

"It's crazy that so many just normal citizens are suffering, dying," he told reporters. "The only thing I hope that soon there is going to be peace in every country. It doesn't matter where."