Novak and Carlos Gomez-Herrera have withdrawn from the Mallorca doubles final, with Gomez-Herrera citing an ankle injury.
The Serbian/Spanish combination will play in the ATP Mallorca doubles final after beating third seeds Oliver Marach and Aissam Ul-Haq Qureshi 6-3, 7-6 (4).
Novak and his doubles partner Carlos Gomez-Herrera recorded a 4-6, 7-6 (3), 10-8 victory over top seeds Marcel Granollers and Horacio Zeballos to progress into the Mallorca Championships semi-finals.
Novak moved into the last four of the inaugural Belgrade Open, following a 6-1, 6-0 victory over Federico Coria. For a spot in the ATP 250 event final, the top seed will face qualifier Andrej Martin (SVK, ATP #119).
Novak recorded a 6-2, 7-6 (4) win over lucky loser Mats Moraing to progress into the last eight at the Belgrade Open. Next up for the world no.1, who is pursuing his second title of the season, is Federico Coria (ARG, Alt), currently ranked no.96 in the ATP Rankings.
The third seed clinched the biggest victory of his career against world no.1, triumphing 7-5, 4-6, 6-4 in three hours and 25 minutes to reach the Serbia Open final.
The world no.1 moved into the Serbia Open semi-finals on Friday following a 6-1, 6-3 victory over countryman Miomir Kecmanovic. He will next face Russian third seed Aslan Karatsev (H2H 1-0).
Top seed began his Serbia Open 2021 campaign with a routine 6-1, 6-3 win against Kwon Soonwoo to reach the last eight in his hometown. He will next face fellow Serbian Miomir Kecmanovic on Friday.