Ash Barty has become the first woman since Lindsey Davenport in 2001 to win both the singles and doubles titles in Stuttgart.
The World No.1 celebrated her birthday weekend by winning two titles - and a brand new sports car - at the Porsche Tennis Grand Prix after a third consecutive comeback triumph in the singles final against Aryna Sabalenka.
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To complete another landmark week, the 25-year-old then won the doubles title with American partner Jennifer Brady.
Barty had just over an hour's rest before joining forces with her friend, Australia Open finalist Brady, to beat the top-seeded US pairing Bethanie Mattek-Sands and Desirae Krawczyk 6-4 5-7 [10-5].
It made Barty the first reigning World No.1 since Justine Henin in 2007 to win in Stuttgart and the first since Davenport 20 years earlier to win both finals at the same tournament there.
"It's extremely humbling to be even mentioned in the same sentence as both Justine and Lindsay, they're both legends of the game," she said.
After her singles win, Barty was presented with her 68,570 Euros ($A107,074) winner's cheque and a brand new Porsche.
It was another performance full of skill and resilience to dismantle the Belarusian's power game and win 3-6 6-0 6-3 for her third singles title of the year.
For the third day running after come-from-behind wins over Karolina Pliskova and Elina Svitolina, the Queenslander dug deep on the indoor clay after dropping the first set.
Sabalenka, who needed a medical timeout at the end of a second set drubbing, was in tears at one of the changeovers in the deciding final set, struggling not just with a heavily-strapped right thigh but also with Barty's supreme, bamboozling all-court game.
Sabalenka said she had been suffering a lot of pain from an adductor muscle issue that had flared up in the first set.
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The triumph, Barty's 10th successive over a fellow top-10 player, saw her shoot to the top of the WTA's 'Race to Shenzhen', the order of merit system that identifies the year's top woman player.
It was her first European tournament on clay since triumphing in the 2019 French Open and she looked in the sort of form to regain the trophy that she decided not to defend last year.
"There is a first for everything, isn't there?" laughed Barty after being asked if it was the first time she'd won a bright green Porsche and two titles at the same tournament.
"This week's been phenomenal for me. I've certainly felt like I'm taking my tennis to a kind of a new level in a sense of being able to be calm and play with freedom and play without consequence in a way."
Her singles victory had been beautifully constructed after Sabalenka's destructive hitting helped her earn her the one crucial break for 5-3 in the opener but Barty's response was remarkable, as she reeled off nine straight games.
Soaking up the pressure and mixing up her responses with immaculate angles and depth to her shot-making, Barty was at her brilliant best on a lively indoor clay-on-boards surface she'd never experienced before.
And although Sabalenka fought on, Barty, who hammered 26 winners and broke the Belarusian's delivery five times, held off her attempt at one last show of defiance to prevail in one hour 47 minutes.
"She's No.1, she's on top - and she's a great player," was Sabalenka's verdict, one that is being shared throughout the game.
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