Nadal is playing his first official event since winning his 16th major title at the U.S. Open last month while Dimitrov looks to reach the final in Beijing for a second straight year.
Nadal has been tested thus far
Handed a difficult draw, the Spaniard was nearly eliminated in the first round at the hands of Frenchman Lucas Pouille, saving two match points in a 4-6, 7-6 (6), 7-5 win.
Nadal looked better in his second round victory over Karen Khachanov, winning by a 6-3, 6-3 scoreline while avenging a loss to American John Isner from last week's Laver Cup, taking out the big-serving Isner 6-4, 7-6 (0) in the quarterfinals.
Dimitrov has been pushed
It's been a rocky road for the Bulgarian as well, needing three sets to quell the challenge of Damir Dzumhur 6-1, 3-6, 6-3 in the first round. Dimitrov followed that up with his first-ever win over Juan Martin Del Potro 7-6 (5), 7-5 after trailing in both sets.
In the quarter-finals, the world number eight fought off a challenge from Spaniard Roberto Bautista Agut, winning 7-6 (5), 4-6, 6-2 to set up a showdown with Nadal.
The prior history between the two is heavily slanted in Nadal's direction. Owning an 8-1 lifetime mark against Dimitrov, the Spaniard won their most recent meeting, a five-set thriller in the semifinals of this year's Australian Open.
Nadal expecting tough game
The 16-time Grand Slam champion is expecting a difficult match: "Tomorrow will be a tough one, for sure. He's playing well. He had a good victory today. Let's see. I going to try to play my best. I hope to be ready for it.”
Dimitrov back at site of only win against legend
The lone victory for Dimitrov against his Spanish rival was in this event last year, an emphatic 6-2, 6-4 win that propelled the Bulgarian into the semifinals.
Last year's match saw Dimitrov break the Nadal serve five times and he spoke of his delight with the triumph: ''I'm pretty happy with that win,'' Dimitrov said. ''I'm not going to lie. I've played Rafa quite a few times. So many times I was close or a couple of times I was cramping.
"There was just always something happening. Today, I just played an excellent match. Simple as that. I'm proud. A lot of the work is paying off.''