The 23 year-old Croatian then got the packed crowd cheering as she moved the bar up to 2.02m and cleared it on her first attempt, before taking three tries to jump 2.04m with spectators now transfixed on the 193cm tall athlete.
Having cleared 2.04m, one centimetre below her personal best, Vlasic consulted her coach and father Josko, a former decathlete, before deciding to go for a world record of 2.10m, to better Bulgaria's Stefka Kostadinova's 2.09m set back in 1987.
With the crowd getting right behind her, the Split-born jumper took three attempts but narrowly failed to clear the bar, with Kostadinova's 20-year record still standing, but only just.
"I just want to thank the crowd for their great support," Vlasic said in a trackside interview.
"I will definitely be back next year."
World lead
Earlier, Vlasic failed with her first jump of the competition at 1.85m, but then put together a string of seven consecutive successful attempts to take her up to the 2.04m mark.
The 2.04m eclipses her previous meet record of 1.97m set at last year's event, which she jointly held with Sweden's Kajsa Bergqvist, and is easily this year's best effort, surpassing Mexican Romary Rifka's 1.95m set in March.
Hellebaut, who will remain in Doha to train for another week, began strongly but stumbled at 1.96m and 1.98m before finally failing to clear 2.00m.
 |
USA's Virginia Powell, centre, powered to victory in the women's 100m hurdles and set a new meet record of 12.66 seconds [Al Jazeera] |
Skolimowska hammers opposition
Meanwhile, Polish hammer thrower Kamila Skolimowska set a new meet record in a star-studded field, with a throw of 76.83 metres on her third attempt out of four, beating world record holder Tatyana Lysenko of Russia who threw 75.73m.
Skolimowska's 76.83m beat world champion Olga Kouzenkova's old meet best of 71.57m set in 2001, with the Russian only managing ninth place this time with 63.87m.
In the women's 100m hurdles, America's Virginia Powell set a new meet record of her own with a win in 12.66 seconds which is also a new world lead.
Powell, who got off to a slow start, overhauled the field to beat compatriot Lolo Jones (12.78) into second place and Australian Sally McLellan (12.90) into third, with her time bettering Jamaican Michelle Freeman's old meet best of 12.72 set in 1998.