Sabastian Sawe has always had a propensity to surprise.

Having never competed on the road, the Kenyan began the 2022 Seville half marathon as a pacemaker, proceeded to drop everybody within the first 10km, and carried on to claim victory in a course record time.

Running the second-fastest marathon debut in history in Valencia in 2024, Sawe again hinted at his potential.

That time of two hours two minutes five seconds was only 12 seconds slower than the late Kelvin Kiptum's first marathon two years earlier, before Kiptum went on to break the world record in Chicago in 2023.

There were signs.

But they were far from sufficient to prepare anyone for the momentous occasion which unfolded on a perfect April morning in London on Sunday.

Sporting immortality, secured in 1:59:30.

Speaking to BBC Sport 24 hours after making history as the first person to run a sub-two-hour marathon in a competitive race, Sawe said the time came as a surprise even to him, with his focus primarily on retaining his title.

"It was not in my mind. I was well prepared for this year's London Marathon, but what comes surprised me because I was not thinking to run a world record."

But Sawe, 31, says he can go even faster.

"It was possible to run faster yesterday," he said. "Even 1:58 is possible."

Sawe, born in Kenya's Rift Valley, where his father worked as a maize farmer, declared it "a day to remember" after obliterating Kiptum's world record by 65 seconds.

Others searched for the words to pay appropriate tribute to an accomplishment once considered impossible.

"Nobody thought that a sub-two-hour marathon under World Athletics conditions would be done in their lifetime," London Marathon race director Hugh Brasher told BBC Sport.

"This is an unbelievable day for sport. It is sport and history in the making."

Former women's marathon world record holder Paula Radcliffe said: "We've witnessed history being made, but it is more than that.

"It is an iconic barrier that there has been this discussion over for a long time about whether it is even possible."

Sawe had to remain patient for his breakthrough, one which at times appeared might never come.

Raised predominantly by his grandmother, he moved to Iten to pursue his running ambitions in 2017, but his time in Kenya's 'home of champions' failed to produce the desired results.

It was at a point when his dreams could not have felt further away that he was introduced to the man who has assisted him to greatness - Italian coach Claudio Berardelli.

As injury and the postponement of races caused by the coronavirus pandemic left Sawe struggling to make a living through running, his uncle, Uganda's 800m record holder Abraham Chepkirwok, put him in touch.

It proved a pivotal intervention.

Berardelli, an esteemed coach in Kenya who has described Sawe as a "special one", instantly recognised his marathon potential and moved him away from the track.

He says Sawe, whose success he puts down to physiological advantages paired with an excellent attitude, is far from reaching his full potential only four races into his marathon career.

Sawe backed up his 2:02:05 debut with major victories in London and Berlin in 2025 - in 2:02:27 and 2:02:16 respectively - and had targeted the world record in the latter before that bid was ended by the 25C heat.

Sawe achieved his world record in London despite suffering a stress fracture in his foot following Berlin, while a back issue which left him "almost giving up" in January delayed his preparations until early February.

It is also notable that he ran the historic time in London, a course considered slower than Berlin and Chicago and which had not witnessed a men's world record since 2002.

The great Eliud Kipchoge became the first man to run a marathon in under two hours in 2019, on a course with only 2.4 metres of incline, which was not record-eligible as it was held under controlled conditions.

Even more astonishing in London was that debutant Yomif Kejelcha also went sub-two, and half marathon world record holder Jacob Kiplimo also beat Kiptum's former record.

Kipchoge wrote on Instagram: "Today is a historical day for marathon running!

"Seeing two athletes break the magical two-hour barrier at London Marathon is the proof that we are just at the beginning of what is possible when talent, progress and an unwavering belief in the human potential come together.

"My deepest congratulations to both Sabastian Sawe and Yomif Kejelcha. Breaking the sub-two-hour barrier in the marathon has long been a dream for runners everywhere, and today you've made that dream come true."

At the finish line, Sawe held up sponsors Adidas' latest 'supershoe' with his time written along the side, acknowledging the technology which had assisted him.

The Adidas Adios Pro 3 shoes, available to purchase for an eye-watering £450, weigh just 99g - 30% lighter than the previous model.

The company claims they deliver an 11% greater forefoot energy return and improve running economy by 1.6% compared to its predecessor. Tigst Assefa also wore the shoes in breaking the women-only record on Sunday.

To benefit from those statistics, however, Sawe runs about 200km per week - averaging almost 30km every day - at altitude, and credited his increase in volume as one of the key factors in his progress.

Developments in fuelling have also aided progress in endurance events. Sawe reportedly took on 115g of carbohydrates per hour during the race, following a breakfast consisting of two slices of bread with honey and tea.

It all combined to allow him to cover 26.2 miles at an average pace of 2:50 mins/km, or 4:33 mins/mile, including a 5km split of 13:42 from 35-40km as he sped up towards the finish.

However, amid the spate of high-profile doping cases involving Kenyan athletes, including women's marathon world record holder Ruth Chepngetich, he has also had an awareness for the need to instil confidence in these performances.

Determined to prove he is competing clean, Adidas provided $50,000 (£36,900) to the Athletics Integrity Unit, the sport's anti-doping body, to frequently test Sawe over a 12-month period.

That began with a reported 25 out-of-competition tests in the lead-up to Berlin in September, continuing at a similar rate as he prepared for London.

Sawe said on Monday: "It's very important to me because it gets out the doubt in my career of athletics and yesterday's performance.

"It shows Sabastian Sawe is clean. It shows running clean is good, and we can run clean and we can run faster.

"It keeps the awareness that Sabastian Sawe is not to be doubted, and he is a clean athlete."

Wherever Sawe goes next, with his coach backing his claim that there is more to come, the world will be watching.