Petra Kvitova claimed her second Qatar Open title in her third final in four years with a 6-2 6-1 win over Garbine Muguruza.
Victoria Azarenka's back injury allowed Garbine Muguruza to progress to the Qatar Open final, where Petra Kvitova awaits.
After losing out to Aryna Sabalenka in the final last year, Petra Kvitova is edging closer to a second title at the Qatar Open.
Aryna Sabalenka's hopes of retaining her Qatar Open title are over, but the top two seeds remain alive in the draw.
Madison Keys had not played on tour since September, but the American looked in good shape as she began her season in Doha.
There were wins for Victoria Azarenka, Garbine Muguruza and Jelena Ostapenko in the first round of the Qatar Open.
Serena Williams was working hard on the practice courts with former men's world number three Grigor Dimitrov ahead of the Miami Open.
Iga Swiatek's first career title was her shock French Open victory in October, but now the Polish teenager has added another in Adelaide.
Iga Swiatek reached her first final since winning the French Open and will tackle Belinda Bencic after the Swiss edged out Coco Gauff.
Danielle Collins' injury allowed Iga Swiatek a straightforward progression in Adelaide, but Coco Gauff had to rally to remain alive.