Mo Farah overcame a crippling early stitch to defend his world 5,000m title and claim a rare world and Olympic double in the long-distance events.
In what will be reassuring news to amateur runners across the globe, the Briton admitted that he was hoping for a slow pace in Friday's race to recover from his stitch.
"Early in the race I had a big stitch so I was hoping the pace wouldn't go as fast and it didn't, it all went well and I just tried to stay out of trouble," said Farah, who won an emotional double gold at the Olympics last year in the Somalia-born athlete's adopted home city of London.
The Briton described his victory at the Luzhniki Stadium on Friday as the runaway best of his career, which has blossomed since he teamed up with Alberto Salazar in Portland, Oregon.
The victory, with Ethiopian Hagos Gebrhiwet taking silver and Kenyan Isiah Koech bronze, coming just six days after Saturday's 10,000m win "was definitely the sweetest by far".
"The double was definitely tougher than the Olympic one because last year nobody knew what I was capable of. Today was indeed one of the most important days in my career, but I'm the same old guy," he said.
"I had a stitch and it was important I had to try and get over it. My legs felt okay. I was a lot more heavy than the other guys because they didn't run the 10,000m.
"I thought the race would have gone harder, thinking the guys were thinking 'he's already done 25 laps around the track plus the heats for the 5000m', but it didn't."
In a sprint finish, started when Farah bolted with 650 metres to race, the Briton acknowledged that he had been confident in his ability to hold off the attentions of Gebrhiwet, Koech and another Kenyan, Thomas Longosiwa.
"I was confident from having run fast 1500m races in last few races," he said in reference to his decision to step down from the 5,000 and 10,000m in order to hone his speed, notably resulting in an unlikely European record in the 1500m in the Monaco Diamond League meet.
"I was confident of my speed if it came down to the end, and to come home strong."
Farah added that he was concerned he might have been boxed in as part of Kenyan team tactics, but that never materialised.
"That didn't happen and I was able to go in front and control the race," the 30-year-old said, confirming that the marathon would be his focus from 2014.
In winning the double-double, Farah emulated Kenenisa Bekele's similar exploits at the 2009 worlds in Berlin, which followed his victories in the 2008 Olympic Games in Beijing.
But he said Bekele's world records over both distances were not on his immediate radar.
"Since last year I've been concentrating on the world championships and trying to win medals," he said.
"It's very difficult to try and prepare a fast time in a championships. In a championships you just have to try to cover every move, (have) endurance and speed.
"Tactically, I've learned a lot in my career. Many people forget that I just didn't come overnight, but it's been years of struggle.
"I made the breakthrough with Salazar, improving one or two percent, that's the difference to becoming champion to finishing fifth or sixth."
Farah added: "As an athlete, the important thing is trying to win medals in my career."