This year was a season of resurgence for Barbora Krejcikova and Katerina Siniakova. The Czech duo, an established partnership dating back to their junior days, qualified for their third straight WTA Finals, with their best results since 2018. Their four titles include one Grand Slam and the Olympic gold medal, and their overall win-loss record is 35-10 through the end of Indian Wells.

We look back at the moments that defined their season:

Australia: Back in the big time

Krejcikova and Siniakova swept their way through the juniors, and in 2018 - their first full season together at pro level - they proved they could dominate the WTA Tour as well. That year, they won Roland Garros and Wimbledon back to back and finished joint World No.1 after coming runner-up to Timea Babos and Kristina Mladenovic at the WTA Finals.

Road to the WTA Finals: Sabalenka reaches new heights in 2021

But entering 2021, they had not managed to reach another Grand Slam final since Wimbledon 2018, and had won only three titles in that timeframe. Both of those were rectified immediately in Australia. Krejcikova and Siniakova won the Gippsland Trophy and backed it up with a run to the Australian Open final, losing out to Elise Mertens and Aryna Sabalenka.

Dominance on clay

The spring hardcourts were less favourable to Krejcikova and Siniakova, who lost before the final in each of Doha, Dubai and Miami. On the terre battue, though, they soared.

The Czechs captured a seventh title together, in Madrid, defeating Gabriela Dabrowski and Demi Schuurs in the final. That was the precursor to a brilliant Roland Garros, where they dropped just one set - to Dabrowski and Leylah Fernandez in the third round - en route to their second French Open crown and third major trophy.

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Champions Corner: Krejcikova and Siniakova reflect on 'unreal' season after Madrid win

This was all happening in conjunction with Krejcikova's stunning singles breakthrough. After being crowned Roland Garros singles champion as an unseeded outsider, the next day she delivered as a favourite in the doubles final. Krejcikova and Siniakova, the No.2 seeds, dispatched No.14 seeds Bethanie Mattek-Sands and Iga Swiatek - a result that meant Krejcikova became the first woman to pull off the Parisian double of singles and doubles titles since Mary Pierce in 2000.

Golden glory

Wimbledon ended in disappointment for Krejcikova and Siniakova, who were unable to pull off a second Channel Slam after missing four match points against Veronika Kudermetova and Elena Vesnina in a 6-7(6), 6-4, 9-7 quarterfinal thriller.

Road to WTA Finals, singles

Road to WTA Finals, doubles

But a month later, they got their revenge, eking out the Russian duo 6-3, 3-6, [10-6] in the Tokyo Olympic Games semifinals. It was the third match tiebreak in a row that Krejcikova and Siniakova had won, but after taking the long route to the final, the gold medal match would be a smoother ride.

The Czechs defeated Belinda Bencic and Viktorija Golubic 7-5, 6-1 to win their first Olympic medals - and break new ground for their country. The Czech Republic had enjoyed a long tradition of Olympic tennis medallists, particularly in women's doubles, where two teams had previously won the silver medal (Helena Sukova and Jana Novotna in 1988 and 1996, and Andrea Hlavackova and Lucie Hradecka in 2012). But Krejcikova and Siniakova were the first to bring home gold since the Czech Republic became an independent nation in 1993.