Top seed Roger Federer beat Australian wildcard James Duckworth 6-0 6-1 in 39 minutes to reach the Brisbane International semi-finals.
The 33-year-old's victory came just 24 hours after he struggled to see off world number 153 John Millman.
Federer, last year's runner-up, will face fourth seed Bulgarian Dimitrov, who beat Martin Klizan 6-3 6-4.
"I'm happy I had a match like this after yesterday," said Switzerland's 17-time Grand Slam winner.
"I felt tired. This morning, I had muscle pain and all that stuff. So I'm very happy I got it done quickly today."
Japan's Kei Nishikori meets Milos Raonic in the other semi-final as players warm up for the Australian Open, which starts on 19 January.
Nishikori, the 2014 US Open runner-up, beat Bernard Tomic 6-0 6-4, while Raonic's booming serve helped secure a 7-6 3-6 7-6 victory over Australian Sam Groth.
Dimitrov, a beaten Wimbledon semi-finalist alongside Raonic, set up the Federer encounter with a comfortable 6-3 6-4 success over Slovakian Martin Klizan.
Federer will be seeking his fifth Australian Open triumph in the 2015 tournament.
|Federer's whirlwind success|
|World number two Federer won the first set in 16 minutes and the second in 23||The Swiss won 90% of his first serves and fired down 12 aces|
|He hit 24 clean winners past 125th-ranked Duckworth, who could not manage any||Francisco Clavet set an ATP record for the quickest victory when beating Shan Jiang 6-0 6-0 in 25 minutes in Shanghai in 2001|
In the women's draw, Ana Ivanovic set up a final showdown with top seed Maria Sharapova, by edging Varvara Lepchenko 7-6 (7/2) 6-4.
Serbia's world number seven will compete with Russian Sharapova for the trophy after the reigning French Open champion defeated Ukrainian Elina Svitolina 6-1 6-3.