KUALA LUMPUR: Debutante Shereen Samson Vallabouy was annoyed with herself for making a tactical error in the women's 400m heats at the World Athletics Championships in Oregon, United States.
The US-based athlete, a wild card entry, feared she was out too fast in the first 150 metres of the race and decided to slow down a little and pace herself accordingly
Shereen, however, could not maintain her tempo as she clocked 53.56s to finish seventh out of eight runners in Heat Six at Hayfield Stadium on Sunday.
The mark was almost a second slower than her personal best of 52.68s, set this year in the US.
Many expected Shereen to break the 29-year-old national mark of 52.56s set by Rabia Abdul Salam after her smashing runs in collegiate competitions in the US.
There were six heats in the 400m, and only the top three of each race made the next round.
Poland's Anna Kielbasinska (50.63), Candice McLeod of Jamaica (50.76) and Victoria Ohuruogu of Britain (51.07) finished top three in the heats.
The 24-year-old Shereen, a recreation and tourism undergraduate at Winona University in Minnesota, said: "The race did not go as well as I wanted it to be.
"I made a tactical mistake with my pace.
"I am disappointed in myself, but I think it is important to learn from the mistake.
"And I must forget about this hiccup and shift my focus on the Birmingham Commonwealth Games (from July 28 to Aug 8)," said Shereen, who will be making her Games debut in Birmingham.
"I must thank the Malaysian Athletics Federation for giving me the opportunity to compete in the World Championships," added Shereen, who is only the second Malaysian female athlete to take part in the World Championships in 11 years.
Shereen has two weeks to iron out her weaknesses before her 400m event on Aug 2 in Birmingham, which will be her final assignment of the season.
Only two Malaysians competed at the World Championships.
On the first day of competition on July 15, high jumper Nauraj Singh Randhawa, who qualified on merit, had a disastrous outing.
The Germany-based athlete suffered an ankle injury and failed to clear the starting height of 2.17m in all three attempts. His next competition is the Commonwealth Games.