The 24-year-old continued his unbeaten run over this distance in 2017 by crossing the line, wearing his country’s flag as a cape, in a national record time of one hour, 18 minutes and 53 seconds.
“I am very happy. This is great for Colombia. I thank god for this triumph,” he told reporters.
“It was a complicated competition but I was prepared physiologically and physically. In the last 4km I decided to make it quicker and ultimately the last kilometre was decisive.”
Russian Sergey Shirobokov, competing as an authorised neutral athlete, shadowed Arevalo for most of the race but faded on the final lap on The Mall.
The 2015 youth champion still managed a late surge to finish two seconds behind Arevalo to take silver in his debut senior World Championships.
Shirobokov dedicated his medal to the Russian athletes who were not authorised to compete in London, owing to the country’s ban from athletics following an independent WADA report revealing widespread doping offences.
“I am so young. These are my first world championships so I’m so glad to win this medal. I wanted to win the gold but I couldn’t today,” he said.
“My goal was to compete for other Russian athletes who have been banned. It was a great motivation to be here. I wanted to win for them.”
Caio Bonfim repeated his performance from the Pan American Games two years ago to take bronze in 1:19:04 for Brazil’s first medal of any colour at the championships in London.
Overtaking a tiring Lebogang Shange of South Africa in the final stages, Bonfim made sure he improved on his fourth place finish at his home Olympics last year.
But the day belonged to Arevalo who was in the thick of the leading pack as it dwindled down from eight at the 15km split, to three in the final kilometre.
Arevalo showed a huge improvement on his last 20km showing on this course at the London 2012 Olympics where he finished 20th.
However, there was disappointment for British hope Tom Bosworth on home ground as he was shown three red cards for technique infractions – meaning automatic disqualification – just past the halfway point.
“I haven’t been disqualified for four and a half years so to do it here in London is devastating. But this has only made me hungrier for more. These bad days make the good days even sweeter,” he said.
(Reporting by Christian Radnedge; editing by Rex Gowar)