Humidity is expected to range between 10 per cent and 75 per cent today
A day after clinching a nearly three-hour semi-finals duel with Naomi Osaka, the world number two overcame a mid-match blip to triumph 6-4 4-6 7-5 in the final at the Pat Rafter Arena.
Pliskova rode her big first serve to save two break points in the first set and converted on her first opportunity to surge ahead.
A set and break down, Keys broke back to level it 3-3 and went on to win the set and force a decider, in which the first six games stayed on serve before Pliskova broke the American in the seventh.
Keys refused to throw in the towel, however, and foiled the Czech's first attempt to serve out the match at 5-4.
Pliskova could not be denied though.
The 2017 and 2019 winner broke again for 6-5 and then served it out to clinch victory in her first meeting with the eighth seeded American in a little over two hours.
"I think what's more special than winning is that I finally defend," Pliskova said after her first successful title defence.
"That's always harder. But, yeah, it took me a couple of years to do it, but pleased with that."
Pliskova, who has had considerable success indoors, made no secrets of her fondness for the Pat Rafter Arena.
"It feels more like an indoor court," said the 21-year-old, whose 42 aces in the tournament will translate into $8,400 towards bushfire relief in Australia.
"The conditions are perfect for me indoors - no wind, no sun... so I can hit with full power."
Keys said she was surprised by Pliskova's anticipation.
"Even if you'd say movement isn't her strength, she covers the court really well which makes you start to go for a little more," she said. Results
Final
Singles
Karolina Pliskova (CZE x2) bt Madison Keys (USA x8) 6-4, 4-6, 7-5
Doubles
Hsieh Su-Wei (TPE)/Barbora Strycova (CZE X1) bt Ashleigh Barty (AUS)/Kiki Bertens (NED) 3-6, 7-6 (9/7), 10-8
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