The 20-times Grand Slam champion will now look to avenge his shock defeat by the 20-year-old Tsitsipas in the Australian Open fourth round in January.
Victory for the Swiss, a seven-times winner in Dubai, will make him only the second man in the Open Era to win 100 titles after American great Jimmy Connors who has 109.
Earlier, Tsitsipas recovered from a set and 1-3 down to get past Gael Monfils 4-6 7-6(4) 7-6(4) with the result set to propel him into the top 10 for the first time in his career.
"The whole match changed out of nowhere," Tsitsipas said.
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"I've improved since last year. Beating the big guys, big players, players that have been in the top 10, it means a lot.
"I wanted to get there at some point myself, and I made it today. I don't know, it's probably a special day for Greece."
(Reporting by Shrivathsa Sridhar in Bengaluru; Editing by Christian Radnedge)
