WATCH the ATP Tour LIVE in Australia on beIN SPORTS | Sign up here

Murray's first-round clash with Hanfmann was suspended due to rain, with the three-time grand slam champion 7-5 4-1 down.

He had earlier fumed at umpire Greg Allensworth as pollen rained down on the court in Switzerland, questioning why play had not been stopped.

The rain may have frustrated Hanfmann's victory pursuit on Monday, but it only provided a temporary reprieve for Murray as the players returned to complete the match the next day.

Hanfmann held his nerve through his final two service games to book a meeting with Djokovic for Wednesday.  

In Tuesday's other early match, four-time grand slam quarter-finalist David Goffin was beaten in straight sets by Nicolas Moreno De Alboran.

The likes of Denis Shapovalov and Tallon Griekspoor are also in action in Switzerland on Tuesday, with Taylor Fritz and Casper Ruud joining Djokovic in entering for the second round on Wednesday.