Your Daily Dose: 5 memorable matches from WTA Finals Singapore

This was one of the best matches from the inaugural WTA Finals Singapore, with world No. 1 Serena Williams taking on her good friend Caroline Wozniacki. The match, which took place just a day after the pair attended a Mariah Carey concert together, saw both put friendship aside.

Wozniacki, unbeaten in the round-robin stage, was seeking to avenge her US Open final loss to Williams. The Dane started strong to take the first set 6-2, frustrating Williams such that the American smashed her racket. Williams won the second set 6-3 then held a match point in the decider, which Wozniacki saved through some quick net play that ended with a volley winner. Williams converted her fourth match point to win 2-6, 6-3, 7-6 (8-6).

Any match featuring Agnieszka Radwanska - whose nicknames include "La Profesora" (the teacher) and "The Magician" for her crafty, clever shot-making - is almost always guaranteed to be entertaining.

Her opening match here, where she was the defending champion, had all of that and more - both from the Pole and from her opponent Svetlana Kuznetsova.

The Russian cut her hair while trailing 0-2 in the third set, and continued to find ways to combat Radwanska's drop shots and slices.

Kuznetsova won 7-5, 1-6, 7-5, explaining after the match that her hair was "bothering (her) a lot" as she hit her forehand, and she had thought: "What's more important now: my hair which I can let grow, or the match?"

Garbine Muguruza claimed a decisive 6-3, 7-6 (7-4) win over fellow WTA Finals debutante Lucie Safarova. The Spaniard plays a powerful game, and it was with this power that she dominated the first set. The Czech regrouped to break early and lead 3-1 in the second set but Muguruza fought back to seal victory.

Venus Williams made history by becoming the oldest woman to reach the final of the tournament at 37 when she beat Frenchwoman Caroline Garcia 6-7 (3-7), 6-2, 6-3. An evenly matched first set started with aggressive play from Garcia. Unforced errors were Williams' undoing in the tie-breaker, as her opponent took the first set. The deciding set was close as both players held serve for the first seven games, until Garcia faltered.

The last WTA Finals match to take place in Singapore featured two first-time finalists of the season-ending showpiece. Both entered the title decider undefeated.

On paper, Sloane Stephens had the advantage over her opponent, as Elina Svitolina had never defeated the American on a hard court in two previous meetings. But the battle was a 2hr 23min contest of athleticism, long rallies and end-to-end running that delighted the crowd at the Singapore Indoor Stadium, who had to be reminded more than once by the chair umpire to remain silent between points.

Both are solid defenders. Svitolina eventually won 3-6, 6-2, 6-2 not because Stephens crumbled, but because the Ukrainian simply refused to yield. The champion said at her post-match press conference that she willed herself to victory by being "very, very tough".