Gabriela DeBues-Stafford trimmed nearly four seconds off her Canadian record in the 1,500 metres, clocking three minutes 56.12 seconds to place sixth in the women's final at the track and field world championships on Saturday.

The Toronto native became the first Canadian woman to dip under four minutes on Aug. 29 in the Diamond League final, six weeks after going 4:00.26 to beat Lynn Kanuka's 33-year-old national mark and set her fifth indoor/outdoor Canadian record of 2019.

Starting on the far outside in Lane 8 on Saturday, DeBues-Stafford came out hard and had a short-lived lead in the first lap. The 24-year-old was fourth after 400 metres (1:03.90) and sixth through 800 (2:06.50) but couldn't close the gap on the leaders.

"It's not enough to be the best right now. Being the best right now means you're one of the best of all-time," DeBues-Stafford told CBC's Scott Russell on Thursday. "It's a ridiculously stacked [event] right now and I'm just excited to be [in] the conversation.

"If you don't get a medal, the next best thing you can hope for is a personal best and that [3:56.12] was massive. I'm super-pumped about that and it's an exciting time to be in the women's 1,500."

WATCH | Gabriela DeBues-Stafford shaves nearly 4 seconds off her personal best:

Canada's Gabriela DeBues-Stafford places 6th with a time 3:56.12, Sifan Hassan claims gold. 7:02

Sifan Hassan of the Netherlands set a championship record with her 3:51.95 winning time on the track at Khalifa International Stadium in Doha, Qatar. The 26-year-old U.S.-based runner finished fewer than two seconds shy of Genzebe Dibaba's 2015 world record of 3:50.07. Dibaba's didn't race in Doha due to a foot injury.

Last year, my race nerves were out of control. ... I was lost and unclear about what the future held for me. — Gabriela DeBues-Stafford, who lowered her Canadian-record time in the 1,500 metres to 3:56.12 on Saturday

Faith Kipyegon set a Kenyan record Saturday, finishing second in 3:54.22, followed by world No. 3 Gudaf Tsegay in 3:54.38. Kipyegon's winning time in the 2017 final was 4:02.59 at London Stadium.

She returned this season after giving birth to daughter Alyn and won at the Prefontaine Classic on June 30 but suffered an adductor (groin) injury that sidelined the 2016 Olympic champion until the Kenyan trials in September.

Dave Moorcroft, who ran a world-record 13:00.41 in the men's 5,000 in 1982, said DeBues-Stafford didn't put a foot down in the wrong spot Saturday in what he called the greatest women's 1,500 in history, in terms of quality.

"No one, realistically, could have asked for more," the CBC Sports analyst said. "If someone had told Gabriela that she would run 3:56.12, she would have expected to be a medallist or very close. She should feel really proud of herself."

To further understand DeBues-Stafford's remarkable season, she was covering the 1,500 in the 4:03 range to end the 2017 campaign. She struggled to distinguish herself a year ago, making just one appearance on the professional Diamond League circuit, placing 11th in 4:07.51 in Birmingham, U.K.

Recommitted to training seriously

"Last year, my race nerves were out of control and taking away from the enjoyment of running," DeBues-Stafford, who ranked fourth in the world entering these worlds, told CBC Sports in August. "I was lost and unclear about what the future held for me, but I have recommitted myself to the sport and training seriously at a high level."

Everything changed last August after DeBues-Stafford joined coach Andy Young's world-class program and began training with British-record holder Laura Muir.

DeBues-Stafford's 2019 Canadian records

Indoor mile: 4:24.80

4:24.80 Indoor 5,000 metres: 14:57.45

14:57.45 Outdoor 5,000: 14:44.12

14:44.12 Outdoor mile: 4:17.87

4:17.87 Outdoor 1,500: 3:56.12

Now living in Scotland with her husband Rowan, DeBues-Stafford said she wants to change the mentality among Canadian athletes of being satisfied to make an appearance at worlds or the Olympics.

"You want to get here, you want to perform and you want to be in the conversation [as a medal contender]," said DeBues-Stafford, who fell short Saturday in an attempt to join former hurdler Perdita Felicien (2003) as the only Canadian women to win an outdoor world title on the track.

"Canada's doing really well now. I had a conversation with [Canadian distance runner] Moh [Ahmed] leading up to [today's race] and he said, 'You've had a great season and now it's just icing [on the cake].' But you can't have the cake without the icing, right? The icing's the best part. I'm excited to be part of this strength in Canadian running right now."

WATCH | DeBues-Stafford: 'I'm really excited about Tokyo' and the 2020 Olympics:

Canada's Gabriela DeBues-Stafford discussing on setting a national record and finishing 6th. 3:02

Last Monday, the Somalia-born, St. Catharines, Ont.-raised Ahmed stumbled after being clipped by an opponent late in the men's 5,000 final in Doha but recovered to earn a bronze medal in 13:01.11 while rookie pro and former NCAA track and cross-country star Justyn Knight of Toronto was 10th.

The next day, Markham, Ont., sprinter Andre De Grasse made it two podium finishes at these worlds when he won silver in the 200 to go with his bronze in the 100.

After Saturday's race, DeBues-Stafford approached training partner Muir of Great Britain and told her "we're going to be in it [the medal mix]" at the 2020 Olympics in Tokyo.

Muir finished fifth Saturday in 3:55.76 after placing fourth (4:02.97) in the 2017 world final. She hadn't raced for nearly two months before travelling to Doha after tearing a calf muscle on July 20 at the Diamond League's Müller Anniversary Games in London.

CBC Sports has exclusive live coverage of the 2019 World Track & Field Championships from Sept. 27-Oct. 6. Visit the stream and broadcast schedule, You can also add the complete event schedule to your calendar.