Istanbul: A world pentathlon record from an athlete overlooked in the pre-competition build-up and hearing problems for the sprinters dominated the first day of the World Indoor Athletics Championships on Friday.

Briton Jessica Ennis' clash with Tatyana Chernova, the Russian who took her world heptathlon title last year, was expected to provide the highlight of the opening day.

Instead Olympic champion Nataliya Dobrynska quietly put together a series of impressive performances to set a world record of 5,013 points.

The Ukrainian's gold medal total bettered the 20-year-old world mark of 4,991 set by Russian Irina Belova and provided a timely reminder of her class ahead of the London Olympics.

"I don't like to be a favourite and always when I'm in the shadows that's good for me," Dobrynska said.

Ennis, the 2010 champion, had led the competition until a disappointing long jump of 6.19 metres in the penultimate discipline, compared to Dobrynska's 6.57 which put her in front.

‘Absolutely gutted'

The Briton took the silver with a score of 4,965 after briefly believing she had won the event. Austra Skujyte of Lithuania was third with 4,802.

"I'm absolutely gutted but at the same time I'm pleased with a PB and a national record so I can't grumble too much," Ennis said.

While she struggled with her long jump, the sprinters were complaining they could not hear the starting gun properly.

After seeing two athletes disqualified for false starts in his 60 metres heat, American Trell Kimmons was determined not to follow them and sat back in his blocks

"I wasn't going to start until everyone else started," Kimmons said.

"There might have been three guns."

Spain's Angel David Rodriquez and American Justin Gatlin were the fastest qualifiers, both running 6.64 seconds. Britain's Dwain Chambers, the 2010 champion, also won his heat in 6.65.

"It was pretty nerve racking," Chambers said.

"You could hardly hear anything from the speaker, which made it very difficult."

Others complained of a double sound or an echo that left them uncertain how to respond.

"It sounds like there are two guns going off all the time," Australian Sally Pearson said after running an Oceania record 7.85 seconds in her first indoor 60 metres hurdles in three years.

"I am just glad I reacted to the first sound I heard."

American Reese Whiting won the first men's title of the championships, with a world-leading throw of exactly 22 metres in the shot put.

Fifth round throw

Outdoor world champion David Storl appeared set to add the indoor gold to his tally after opening with 21.88 but Whiting overhauled the German in the fifth round.

Polish Olympic champion Tomasz Majewski took the bronze.

Meserat Defar comfortably came though the 3,000 metres heats as she attempts to become the first woman to win five successive indoor titles.

The 28-year-old led into the bell and, with Kenya's Sylvia Kibet, pulled away from the field to win in nine minutes 11.76 seconds and qualify for today's final.

"I feel good, I like the track. I'm in good shape," Defar said.

Britain's 5,000 metres world champion Mo Farah and the man he beat to the title, American Bernard Lagat, rode out a roughshod 3,000 metres heat to set up another confrontation in today's final.

Kenyan medal favourite Augustine Kiprono Choge won the race with Farah second and Lagat third in a bunch finish as only 0.2 seconds separated the top four.

‘Ugly race'

"There was a lot lof pushing. It was an ugly race," Lagat said.

World decathlon silver medallist Ashton Eaton was in imperious form in the heptathlon and after four events, was on course to break his world record of 6,568 points.

After winning the 60 metres, Eaton opened the long jump with a personal best of 8.16 metres — the longest distance recorded in any combined events competition.

He finished third in the shot put and high jump for a first day total of 3,654 points, 165 ahead of Ukraine's Oleksiy Kasyanov.