The sprint star held world and European gold medals as a member of Britain’s all-conquering 4x100m relay stable, but still faced needing to find his voice as an individual athlete for the big occasion.
Ujah, who hails from north London, met that test head on and swooped to no fewer than five Diamond League victories two years ago.
As August’s Muller Grand Prix Birmingham rumbles into view, we take a look at a slew of stars who blazed their trail to the top of the sport in the heat of Diamond League competition.
Blazing start
Ujah calls Enfield home, emerging from the Enfield & Haringey club that produced British athletics icons in Seb Coe and Geoff Capes.
CJ broke ten seconds before the age of 20 with a wind-assisted 9.96 in the Netherlands in 2014, the fifth Brit to smash the barrier and the youngest ever to do so.
And a couple of months later he made the step up to slug it out in the senior stakes, earning a third Diamond League cap and finishing fourth at the Birmingham Grand Prix, clocking 10.23.
2015 yielded further gains with victory in the British Championships over James Dasaolu and Ojie Edoburun, going on to match Usain Bolt stride for stride with fourth at the Anniversary Games.
Forging ahead
Missing the indoor season in 2016, Ujah faced a challenging second campaign at Diamond League level, missing out on the top five in four events on the continent.
But it was in Birmingham he found his feet, missing out on gold by a nose in a photo finish with Kim Collins and Michael Rodgers, taking bronze in 10.12 against a slight breeze.
And he found further form at the BUCS Championships, the Middlesex University student breaking the meeting record in his heat and then again in the final.
With his first experience of the Olympic Games ending at the semi-final stage, Ujah faced a critical 2017, to prove to himself as much as others he could deliver on near-limitless potential.
Golden year
The year started superbly – edging Jimmy Vicaut and Ronnie Baker in Rome and laid down a marker with victory at the Anniversary Games in front of a joyous home crowd.
His 9.98 run in Rabat, mere weeks before the IAAF World Championship on home soil, made the sprinting world sit up and take notice.
So the sprinter was crushed when he failed to make the final at the global gathering, a sluggish start in his heat ending his journey at the semi-final stage.
He stepped onto the start line in the second city just 16 days later with a point to prove, then, to show his early-season heroics were anything but a flash in the pan.
Defining display
After Adam Gemili’s false start, Ujah picked up perfectly, driving past Dasaolu alongside him and holding off a late charge from Zharnel Hughes, clocking 10.08 to grab gold.
“I was optimistic coming into this race and you can see my current mindset in my result,” said Ujah, coming through the mixed zone at the Alexander Stadium.
“I am very confident at the moment. There is plenty to build on but I know I'm capable of winning. Getting a win here is massively motivating for me.
“The British crowds have been incredible. To be introduced as a world champion was crazy.”
That the win was followed by a sensational sub-ten victory in Switzerland to close out the season showed just how much confidence Ujah took from the title in front of home support.
Ujah continues to excel at the highest level and individual wins at Diamond League have gone hand-in-hand with relay success, the man entrusted with giving Britain a flying start over 4x100m.
With European relay gold ensuing in Berlin last year, you can look back to Birmingham and the Diamond League to see how one of the country’s top pacemen proved himself at the highest level.