The swimming world was filled with plenty of fast performances this past weekend as many countries held their national championships, which served as a prime opportunity to qualify for the 2017 FINA World Championships this July in Budapest, Hungary. With that being said, here are some of the fastest, most notable performances from around the world this weekend.

South African National Championships -- Durban, South Africa

​Chad le Clos​ uncorked a 51.29 in the 100m butterfly Saturday in Durban, the fastest time in the world this year by a small margin. China's ​Zhuhao Li​ posted a 51.34 back in March. Le Clos also dropped a solid 1:55.00 in the 200m butterfly Thursday -- the fastest performance so far in 2017.​

​Bradley Tandy​​, a former University of Arizona star, unleashed two sub-22-second 50m freestyles on Saturday. He swam a 21.99 in the prelims and followed it up with an even faster 21.97 in the finals -- both performances well under the FINA "A" qualifying time standard of 22.47.

Canadian World Championship Trials -- Victoria, British Columbia

​Kylie Masse​ was the star of the show in Victoria this weekend. Masse, the 2016 Olympic bronze medalist, torched a 58.21 in the finals of the women's 100m backstroke on Thursday, scaring ​​Gemma Spofforth​​'s​ 2009 super-suit world record of 58.12 from the World Championships in Rome. Masse's time annihilated her own previous Canadian record of 58.66 from the 2016 Olympic Games in Rio. Of note, that swim gives her the fastest time of 2017 by over a second. ​Emily Seebohm​ of Australia sits second with a 59.28 from March.

Masse also posted a 2:07.21 in the 200m backstroke Saturday -- just ahead of ​Hilary Caldwell​,​ who dropped a 2:07.29. These are the top two times in the world this year. Caldwell is the 2016 Olympic bronze medalist and still holds the Canadian record with a 2:06.80 from 2013.

Swim Open Stockholm -- Stockholm, Sweden

Sarah Sjöström of Sweden, the reigning Olympic gold medalist and world record-holder, unleashed a massive 56.26 in the women's 100m butterfly Sunday in Stockholm, which is the fastest time in the world this year by over 0.7 of a second. Sjöström claimed this race using her always impressive backend speed. She closed in 29.79 over the final 50 meters -- the only one in the field, which included ​Katinka Hosszu​, to come home under 31.

Erik Persson​ of Sweden shredded a 2:07.85 in the 200m breaststroke Saturday in Stockholm -- the second-fastest time in the world in 2017. It's worth noting that the only swimmer ahead of him in the world rankings so far is Japan's ​Ippei Watanabe​,​ who broke the world record in January with a 2:06.67, the first sub-2:07 performance in history. Aside from Perrson and Watanabe, nobody else has been under 2:09 in 2017.​

​Michelle Coleman​, also of Sweden, dropped a swift 1:55.64 Saturday in the 200m freestyle to claim the top time in the world this year -- taking this honor from Italy's ​Federica Pellegrini​​, who posted a 1:55.94 just one day before on Friday in Riccione at the Italian National Championships. Coleman finished ahead of the Iron Lady ​Katinka Hosszu, ​who touched second in 1:57.01.​

​Wojciech Wojdak ​of Poland and Henrik Christiansen ​of Norway battled it out in the 1500m freestyle Sunday to post the third- and fifth-fastest times in the world this year, respectively. Wojdak's 14:54.07 sits third, and Christiansen's 14:59.56 sits fifth.

Italian National Championships -- Riccione, Italy

The men's freestyle events were front and center this weekend in Riccione. In the 800m freestyle on Thursday, ​Gabriele Detti​ and ​Gregorio Paltrinieri ​posted the top two times in the world this year by a long shot with a 7:41.64 and 7:48.80, respectively -- the only two performances under 7:50 in 2017.

Paltrinieri, the 2016 Olympic gold medalist, followed that up on Friday with an even more impressive swim in the 1500m freestyle, dropping a monster 14:37.08 -- the top time in the world this year, leapfrogging Detti's 14:48 from March. Detti then popped back onto the scene Saturday to post the second-fastest time in the world this year in the 200m freestyle with a 1:46.38, just ahead of the 1:46.84 le Clos posted in Durban earlier in the week.​

​Federica Pellegrini​ ​posted a 1:55.94 in the women's 200m freestyle, which was the top time in the world until Sweden's ​Michelle Coleman ​came along to top her one day later in Stockholm with a 1:55.64.​
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Of note, ​Gabriele Detti​ unloaded a monster 3:43.36 in the 400m freestyle Tuesday -- the fastest time in the world this year.

Australian Swimming Championships -- Brisbane, Queensland, Australia

​David Morgan​ and ​Grant Irvine​ popped off the third- and fifth-fastest 100m butterfly performances of 2017 in Brisbane on Sunday with a 51.81 and 52.08, respectively.​

​Bronte Campbell​ led a loaded women's 100m freestyle field on Sunday with a blistering 52.85. Campbell split this race beautifully, taking it out in 25.70 and bringing it home in 27.15. ​Emma McKeon ​grabbed the silver with a 53.12. Campbell's sister, ​Cate Campbell​,​ picked up the bronze with a 53.30, and ​Shayna Jack​ touched for fourth in 53.40. However, Cate's 52.78 from prelims is still the fastest time in the world for 2017.​

​Cameron McEvoy ​unleashed a 21.55 in the men's 50m freestyle Sunday, which is the fastest time in the world in 2017. What is even more impressive is that McEvoy was able to put up two solid swims in the same day -- posting a 21.78 in prelims. ​James Roberts ​had a terrific swim as well in finals, posting a 21.91 -- good for the fourth-fastest time in the world this year.​
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​Mack Horton​ led a very strong men's 400m freestyle field with a 3:44.18 -- the second-fastest time in the world this year behind Italy's Detti. ​David McKeon ​touched second in 3:46.90 and ​Jack McLaughlin​ grabbed the bronze only 0.06 of a second behind with a 3:46.96. McKeon's and McLaughlin's swims were good for the fourth- and fifth-fastest performances of 2017.