Iga Swiatek continued her hoodoo over Daria Kasatkina as she breezed through their opening match at the WTA Finals.
Swiatek needed just an hour and 23 minutes to see off Kasatkina 6-2 6-3 in Fort Worth, Texas.
The world number one was in command throughout, her movement and intensity too much for Kasatkina in the Tracey Austin Group encounter.
Swiatek saved all three of the break points she faced and converted four of the seven chances she created for herself.
She sent down 23 winners, her highest tally in a single WTA Finals match, to complete her fifth win over Kasatkina this season.
The Pole is the first player to win five or more matches against the same opponent in a single season since Petra Kvitova against Lucie Safarova in 2014.
With her 46th such win of the year (excluding Billie Jean King Cup matches), she is the first player to win 46-plus WTA main draw matches in straight sets in a season since Serena Williams (66) and Agnieszka Radwanska (46) in 2013.
BREAK POINTS WON
Swiatek - 3/7
Kasatkina - 0/3
Swiatek - 23/18
Kasatkina - 4/9
Swiatek - 1/3
Kasatkina - 1/1