On Wednesday night in Donetsk, Rengereuk showed that her win in Nairobi was no fluke.
She led from the outset, passing 1000m in 3:01.10 and 2000m in 6:02.53.
By this point, Chebwogen already looked spent as Ethiopia’s Silenat Yismaw and Berhan Demiesa were the only ones left in the chasing pack, some 15 metres behind Rengeruk.
But the time the surprise package was done, Rengeruk had handed Kenya their sixth girls’ 3000m title in the 14-year history of the IAAF World Youth Championships, in a world-leading 8:58.74 victory and 13-second lifetime best.
The 16-year-old won a thrilling home-straight battle with the fast-finishing Berhan of Ethiopia, who in turn registered a 9:00.06 personal best from her team-mate, Silenat, clocking a 9:01.63 best for bronze.
Rengeruk, the recent winner of Kenya’s World youth trials, shot off from the gun to enjoy a 50m lead and passed the first kilometre mark in 3:01.10, showing she was on course for a sub-nine-minute time.
Keeping up her pace with a 3:01.43 split to go through the 2000m mark in 6:02.53, Rengeruk still had a comfortable 25 metres to play with ahead of the chasing pack, though in a group of four working tightly together, Demiesa and Yismaw looked menacing as they gradually bridged the gap to 20m with two laps remaining.
Hitting the bell in 7:53.30, Rengeruk attempted to change gear and held off the Ethiopian challenge down the final home straight as Demiesa unleashed a dramatic last-gasp sprint but to no avail as her East-African rival narrowly managed to hold the victory in the dying metres.
Her winning time smashed the previous world-leading mark by almost 10 seconds, as both Demiesa and Yismaw took an astonishing 19 and 17 seconds, respectively off their lifetime bests.
Further back in fourth place, Uganda’s Stella Chesang clocked a 9:11.03 personal best, while Germany’s Alina Reh finished fifth in another best, 9:20.99.
World junior champion Chebwogen, meanwhile, could finish only eighth with a lacklustre 9:27.98 but it was academic as Kenya got off to a golden start.