It was 14th-ranked Dimitrov’s ninth career title and his first since the ATP finals in 2017, the same year he won his first Brisbane title.
“It’s been a while since I held one of these, I’m a little emotional,” Dimitrov said at the trophy presentation. “It’s difficult to describe. Holger, what a competitor.
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“My love affair started 11 years ago in Brisbane and I think it continues.”
Dimitrov hit 33 winners and only 14 unforced errors, with Rune saving break points eight times before Dimitrov finally cracked his serve on the ninth opportunity to deny him a fifth title in the two hours and 13 minutes encounter.
The third game of the first set was indicative of the close struggle. Rune held serve in a game of nine deuces and seven game points, finally fending off a break point at 2-1, 30-40 in a rally of 33 shots.
The 32-year-old Dimitrov finally broke Rune in the eighth game of the second set to lead 4-3. Rune saved two match points in the next game, in which he had a time violation and served an ace at 30-40.
Dimitrov then took the next game to love, serving his eighth ace of the match and finishing on his third match point. Rune had nine aces but also three double faults. The eighth-ranked 20-year-old was bidding for his fifth career title.
“Congrats to Grigor who played an amazing tournament,” Rune said.
“I think we have a lot to build on after this week and hopefully we can go one step further in the Australian Open.”