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Disclaimer: Swim of the Week is not meant to be a conclusive selection of the best overall swim of the week, but rather one Featured Swim to be explored in deeper detail. The Swim of the Week is an opportunity to take a closer look at the context of one of the many fast swims this week, perhaps a swim that slipped through the cracks as others grabbed the headlines, or a race we didn’t get to examine as closely in the flood of weekly meets.
Like many of his countrymen, Canadian breaststroke talent Oliver Dawson stepped up with a big swim on the opening day of the 2025 World Cup stop in Toronto, setting a new National Age Group Record in the 100 breast.
Dawson, 17, fired off a time of 58.54 in the men’s 100 breast prelims, knocking more than four-tenths off the Canadian boys’ 15-17 NAG record of 58.97 set by Gabe Mastromatteo in 2019.
The swim also marked a drop of 1.22 seconds from Dawson’s six-day-old personal best, which he set in 59.76 at the Westmont leg of the World Cup last weekend.
Coming into Westmont, Dawson’s PB stood at 59.93, set this past March.
On Thursday in Toronto, he made the biggest gains relative to his previous PB on the first 50, turning in 27.47 after he was 28.17 in Westmont. He also came off more than half a second quicker, but the opening 50 particularly stands out, especially with it being faster than his best time in the 50, 27.61, which he set in Westmont.
Split Comparison
| Mastromatteo, 2019 | Dawson, March 2025 | Dawson, Westmont 2025 | Dawson, Toronto 2025 |
| 27.74 | 28.35 | 28.17 | 27.47 |
| 58.97 (31.23) | 59.93 (31.58) | 59.76 (31.59) | 58.54 (31.07) |
Dawson also broke his own Alberta Provincial Record for 17-year-olds with his swim, and moves into #8 all-time in Canada in the event.
All-Time Performers, Canadian Boys’ 15-17 100 Breaststroke (SCM)
- Paul Kornfeld, 57.10 – 2009
- Finlay Knox, 57.90 – 2024
- Mathieu Bois, 58.22 – 2009
- Richard Funk, 58.35 – 2016
- Scott Dickens, 58.48 – 2009
- James Dergousoff, 58.50 – 2022
- Gabe Mastromatteo, 58.51 – 2022
- Oliver Dawson, 58.54 – 2025
- Apollo Hess, 58.55 – 2022
- Jason Block, 58.62 – 2016
Dawson’s big-time drop landed him 9th overall in Toronto, narrowly missing out on a lane in the final, with Italian Ludovico Viberti clocking 58.47 to snag 8th in the prelims.
Despite missing out on the final, Dawson still jumped up 11 spots from the 20th-place showing he had in Westmont.
He’ll be one to watch for this weekend as Dawson races the men’s 50 breast on Friday in Toronto and then finishes off the meet with his best event, the 200 breast, on Saturday.
On Thursday night, Dutchman Caspar Corbeau won gold in the men’s 100 breast in a World Cup Record of 55.55, just 27 one-hundredths shy of the world record, while Canadian Josh Liendo stole the show in front of the home crowd by breaking the world record in the men’s 100 fly (47.68) and then claiming the 50 free (20.31) in a new National Record just minutes later.
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A mention for a big swim during the Japanese SC Champs where the 16 year-old Raito Numata (he’ll turn 17 in early November) swam 4.00.93 in the 400 IM R050.xlsx