If you wanted to witness a prime exhibition of mental toughness in sport, it was provided by Julia Goerges yesterday.
The German is one of the most resilient players on the WTA tour and needed all her fighting qualities to prevail over Eugenie Bouchard 3-6, 6-3, 7-6 (8-6) and reach today's ASB Classic semifinals.
She dropped the first set - and came back. She was down 0-3 in the final set - and came back. And she faced a match point at 5-6 in the third set - and defended it with a clutch wide second serve, eventually winning.
And all this in blustery, swirling conditions which Goerges described as the most challenging she has faced in 10 years in Auckland.
"We both made the best out of it," said Goerges. "The biggest part of my game was finding solutions, trying to find ways to come back in that third set, which I did really well.
"With those conditions, sometimes you can't do something, it looks pretty amateur because some balls, you don't know where they are coming and they are just flying anywhere.
"It was probably the toughest here in Auckland. I've had one in Montreal last year as well.
"The wind was swirling around, you had no idea where the wind was coming from, it was just coming suddenly and then the next five minutes gone again.
"You cannot do anything about it, you just have to accept it and stay positive."
In a contest of fine margins, the difference was probably Goerges' assertive approach and ability to dictate the rallies, especially when she advanced to the net.
That certainly sealed the tiebreak, where the world No 14 spurned two match points before converting her third.
"I'm a player who plays for it," said Goerges of her approach on big points. "I don't want to get a mistake on those balls ... I just want to go for it. That's the way I want to play, take it in my hands. Sometimes it's not working out but I want to have it in my hands and it's up to me."
The result was tough on Bouchard, who looked a different player from the one who struggled past Dutch qualifier Bibiane Schoofs in the second round.
Gone was the erratic stroke play and Bouchard also had the right focus, after her near meltdown on court in Wednesday's second round.
The Canadian grabbed an early break in the first set, narrowly avoiding a collision with the umpire's chair as she sprinted to retrieve a Goerges drop shot and then never looked like being headed, as Goerges was being forced into errors.
The defending champion turned the momentum around in the second set. She began to find her range off her forehand wing and wound up her deadly serve.
Bouchard couldn't find a single break point opportunity, while Goerges created four, converting one, before wrapping up the set with an ace.
The final set was a nail-biter. Bouchard edged ahead - with one kneeling backhand shot from the Canadian bringing the crowd to their feet - before a Goerges comeback.
Both players had further chances, with Goerges saving a match point at 5-6 with a courageous second serve under pressure. But Goerges was always going to be favoured in the tie break, given her superior serve and skills at the net, and so it proved.