Maria Sakkari defeated Jessica Pegula 7-6 (8-6) 7-6 (7-4) in the opening match of the WTA Finals on Monday in Fort Worth.

It was a highly anticipated first match after the same two competitors faced off in the Guadalajara Open final just eight days ago, with Pegula taking that contest 6-2 6-3 in convincing fashion.

That final lasted just 71 minutes, but the rematch would be a far more gruelling affair, with the first set alone reaching 73 minutes.

Illustrating the even nature of the contest, both players won exactly 52 out of 104 total points played in the opening set, with both players converting three of their five break point opportunities.

Sakkari created a slight edge in the second set, winning 52 per cent of the points (42-of-81) and creating four break point opportunities to Pegula's one.

Pegula took her only chance to break, and then saved two match points to force a tiebreak, but Sakkari would not be denied as she secured the victory and moved to the top of the Group B standings.

BREAK POINTS WON

Sakkari - 4/9

Pegula - 4/6

ACES/DOUBLE FAULTS

Sakkari - 3/1

Pegula - 3/4

WINNERS/UNFORCED ERRORS

Sakkari - 22/22

Pegula - 22/28