The 29-year-old thrashed his Russian opponent 6-4, 3-6, 6-2 to get hold of his 12th tour-level trophy. I felt like I was too fast on the court today.
He showed all the qualities of a top five player in his 66-minute demolition at the Pat Rafter Arena.
And that seemed to be borne out by the early exchanges, as Medvedev raced into an easy three-love lead in the first set, breaking the Nishikori serve at the first time of asking.
Japan's Naomi Osaka lamented her poor attitude following a straight sets thrashing by Lesia Tsurenko in the Brisbane International semifinals but the US Open victor said defeat came with a valuable lesson.
De Minaur, who announced himself with a semi-final charge in Brisbane 12 months ago, ran and ran in the second set as Tsonga blazed away. "For sure, this is a better start... but playing good tennis [and being] very happy and healthy is one of the best keys for me".
Donna Vekic trounced 2018 finalist Aliaksandra Sasnovich 6-2, 6-0 to reach the women's semifinals, where she will play either fifth-seeded Karolina Pliskova or Ajla Tomljanovic.
Asian, European Stocks Rebound Ahead of US-China Trade Talks
Chinese officials are unhappy with United States curbs on exports of "dual use" technology with possible military applications. Its one-sentence announcement gave no other details of the agenda or who else would take part.
In the men's draw, fourth-seeded Daniil Medvedev, who beat former world number one Andy Murray in his previous match, rallied to knock out another former champion in Milos Raonic to reach the last-four.
"Physically and tennis-wise I think it was flawless".
I played a great match against Dimitrov and today's match was another good tennis.
"I was sulking a bit and there are moments that I tried not to do that".
"Everything was going well for me".
"I had so many chances and I thought I could win in two sets".
The 30-year-old Spaniard missed much of last year with injury, but beat both Stan Wawrinka and world No1 Novak Djokovic on his way to his first title since Dubai last year. "So hopefully this isn't a recurring thing".