OSAKA, Japan - Kenya's formidable men's 3,000m steeplechasers toyed with their rivals before delivering the expected clean sweep, with Olympic silver medallist Brimin Kipruto kicking hardest to claim gold.

Kenya's Brimin Kipruto celebrates after winning the men's 3000m steeplechase at the world athletics championships in Osaka, Japan. Kipruto finished ahead of his teammates Ezekiel Kemboi and Richard Mateelong. [AFP] He came home in 8 minutes 13.82 seconds, some 20 seconds off the world record, ahead of Olympic champion Ezekiel Kemboi and Richard Mateelong.

"We had a plan as a team to run together until the final 400m," Kipruto said. "I am so happy. It's the first time I won a gold medal. We will celebrate as a team, as a country."

Soon after, Janeth Jepkosgei made it a night to remember for Kenya by winning the women's 800m world title, crossing the line in 1:56.04 ahead of Morocco's Olympic silver medallist Hasna Benhassi and Spain's Mayte Martinez.

It was the first time Kenya has won a women's middle distance world title.

But there was sadness for crowd favourite and triple former champion Maria Mutola who pulled up injured while in third place as she rounded the last bend.

Mutola, now 34, has said it is likely her last world championships and it was an inglorious end.

"I decided to go in front and not to wait for the others," said Jepkosgei.

"It's the first gold medal for Kenya (in the 800m) and the first world championship gold for me, and it's also my personal best, so I'm happy."

Other medals went to Estonian Gerd Kanter, who ended Virgilijus Alekna's seven-year world reign in the men's discus with a heave of 68.94m.

Russia's Tatyana Lebedeva clinched the women's long jump title with a leap of 7.03m while American Kerron Clement won the men's 400m hurdles in a time of 47.61 seconds.

Earlier in the day Jeremy Wariner made no mistakes in his 400m heat, while Tyson Gay began his quest for a rare sprint double.

Few favourites for gold are firmer than Wariner and he has been on fire this season, improving his personal best to 43.50 seconds.

His next milestone is Michael Johnson's world record of 43.18 and he has suggested it could fall here, but was in no mood to talk about it Tuesday.

"I feel good, I am fine," he said after running 45.10 in his heat, pulling back almost to a walk before crossing the line.

"The track is good but I do not want to talk about the world record now."

The fastest through the heats was Chris Brown from Bahamas in 44.50.

Less than 48 hours after blowing away Asafa Powell to win the 100m gold, Gay lifted himself for the fastest time (20.08) in the 200m quarterfinals.

"I'm gritting my teeth," said Gay, now into Wednesday's semifinals, who had complained of feeling "sluggish" in the morning heats.

"I'm trying to be strong. Mentally and physically I'm okay, only my left hamstring is bothering me a little bit. But I'm not too worried about that."

Usain Bolt, another Jamaican, dominated US contender Wallace Spearmon in heat two to time 20.13 and looks a serious medal contender.

Gay is bidding to emulate compatriots Maurice Greene and the disgraced Justin Gatlin by landing the coveted 100-200 double.

OSAKA, Japan - Kenya's formidable men's 3,000m steeplechasers toyed with their rivals before delivering the expected clean sweep, with Olympic silver medallist Brimin Kipruto kicking hardest to claim gold.

Kenya's Brimin Kipruto celebrates after winning the men's 3000m steeplechase at the world athletics championships in Osaka, Japan. Kipruto finished ahead of his teammates Ezekiel Kemboi and Richard Mateelong. [AFP] He came home in 8 minutes 13.82 seconds, some 20 seconds off the world record, ahead of Olympic champion Ezekiel Kemboi and Richard Mateelong.

"We had a plan as a team to run together until the final 400m," Kipruto said. "I am so happy. It's the first time I won a gold medal. We will celebrate as a team, as a country."

Soon after, Janeth Jepkosgei made it a night to remember for Kenya by winning the women's 800m world title, crossing the line in 1:56.04 ahead of Morocco's Olympic silver medallist Hasna Benhassi and Spain's Mayte Martinez.

It was the first time Kenya has won a women's middle distance world title.

But there was sadness for crowd favourite and triple former champion Maria Mutola who pulled up injured while in third place as she rounded the last bend.

Mutola, now 34, has said it is likely her last world championships and it was an inglorious end.

"I decided to go in front and not to wait for the others," said Jepkosgei.

"It's the first gold medal for Kenya (in the 800m) and the first world championship gold for me, and it's also my personal best, so I'm happy."

Other medals went to Estonian Gerd Kanter, who ended Virgilijus Alekna's seven-year world reign in the men's discus with a heave of 68.94m.

Russia's Tatyana Lebedeva clinched the women's long jump title with a leap of 7.03m while American Kerron Clement won the men's 400m hurdles in a time of 47.61 seconds.

Earlier in the day Jeremy Wariner made no mistakes in his 400m heat, while Tyson Gay began his quest for a rare sprint double.

Few favourites for gold are firmer than Wariner and he has been on fire this season, improving his personal best to 43.50 seconds.

His next milestone is Michael Johnson's world record of 43.18 and he has suggested it could fall here, but was in no mood to talk about it Tuesday.

"I feel good, I am fine," he said after running 45.10 in his heat, pulling back almost to a walk before crossing the line.

"The track is good but I do not want to talk about the world record now."

The fastest through the heats was Chris Brown from Bahamas in 44.50.

Less than 48 hours after blowing away Asafa Powell to win the 100m gold, Gay lifted himself for the fastest time (20.08) in the 200m quarterfinals.

"I'm gritting my teeth," said Gay, now into Wednesday's semifinals, who had complained of feeling "sluggish" in the morning heats.

"I'm trying to be strong. Mentally and physically I'm okay, only my left hamstring is bothering me a little bit. But I'm not too worried about that."

Usain Bolt, another Jamaican, dominated US contender Wallace Spearmon in heat two to time 20.13 and looks a serious medal contender.

Gay is bidding to emulate compatriots Maurice Greene and the disgraced Justin Gatlin by landing the coveted 100-200 double.