Osako Suguru dug deep with an Olympic berth at stake in the Tokyo Marathon on Sunday (1 March), finishing a Japanese-high fourth in a national record of 2 hours, 5 minutes and 29 seconds.
Osako rewrote his own Japan record by 21 seconds. If no-one else breaks the mark in the final men's qualifying race next weekend, the Lake Biwa Marathon, his place at the 2020 Tokyo Olympic Games is secure.
Birhanu Legese of Ethiopia won the race for the second successive year in 2:04:15 - 17 seconds off the meet record - under clear skies and the temperature close to 12 C at the start.
Israel's Lonah Chemtai Salpeter won the women's event in a race record of 2:17:45.
"This was a race I've been targeting all long. It's not official yet as there's still next week, but I managed to set a new record which I hope I can build on from here", said an emotional Osako, who was in tears during the post-race interview.
"It's been pretty tough for me since I finished third (at the Marathon Grand Championship) in September. I'm just glad I got the job done".
This year's Tokyo Marathon was reduced to a field of less than 200 featuring only elite runners as organisers took measures to combat the outbreak of the coronavirus.
With 145 days to go to the Games, Osako had to fend off an aggressive challenge from Inoue Hiroto, who was in the Japanese lead for a bulk of the journey at a pace that would have shattered Osako's record.
The race had appeared to be slipping away from Osako at the midway point, and even he admitted the thought of fading crossed his mind.
"At around 20 km, 21 km, I thought maybe I was out of it. But I kept believing in myself". - Osako Suguru
Legese and compatriots Sisay Lemma and Asefa Mengstu pulled away from the field ahead of the 30-km mark, when the pacemakers dropped out.
Osako seized the moment, pushed the pace and overtook Inoue with 10 km to go. Inoue struggled to keep up and would never regain the Japanese lead; the 2018 Asian Games gold medallist finished 26th (2:09:34).
Osako cruised from there. The Rio Olympian occasionally massaged his side which began to cramp but with 4 km remaining, felt good about his chances of breaking his record.
"Near 38 km, I thought I could do it. But I didn't want to think too much about it and tighten up. I tried to stay loose", he said.
Turning for home in front of Tokyo Station, Osako - who also collected a 100 million yen bonus for setting a new Japan record - started pumping his fist and let out a scream as he took the tape.
It was a moment of salvation for the 28-year-old star runner, who rebounded from a disappointing third place in last year's Marathon Grand Championship.
"I wasn't marking Inoue specifically but I knew I had to travel at a pace my body was comfortable with. If I try to stay near the front it was going to throw me. So I sat back a little and watched the race unfold, waited for my time", Osako said.
"The place slowed down a little and I managed to catch up. Everyone else looked to be feeling it and I wanted to turn the tide by driving up the pace.
"It was a race full of ups and downs with some concern but in the end, I had a new Japan record. I did everything I could today".
Shitara Yuta, who alongside Inoue was tipped to challenge Osako, never contended throughout the race. The former Japan record-holder ended up 16th in 2:07:45.
Shogo Nakamura and Yuta Hattori, by finishing one-two in the MGC, had the first two spots for Tokyo 2020 sewn up.