The Japanese had set his sights on returning to the world's top five after falling to 39 last April due to a wrist injury.
And he showed all the qualities of a top five player in his 66-minute demolition at the Pat Rafter Arena.
He only served two aces compared with the 11 sent down by Chardy, but Nishikori returned superbly and pressured the Frenchman's serve throughout, breaking him twice in each set.
Nishikori also moved around the court well, his speed not noticeably affected by the injuries that hampered him last year.
"Physically and tennis-wise I think it was perfect. I served well, I returned well -- I think that was the key today -- and I was moving well, that was fantastic."
Nishikori was runner-up to Dimitrov in 2017 and will go into Sunday's final against either fourth-seeded Russian Daniil Medvedev or Frenchman Jo-Wilfried Tsonga as firm favourite.