By Rod Gilmour
BUDAPEST (Reuters) - Lilly King, of the United States, and Russian Yuliya Efimova moved a step closer towards a grudge rematch of their Olympic final duel as they eased into the women's 100 metres breaststroke semi-finals at the world championships on Monday.
King beat Efimova, twice banned for doping offences, at the Rio de Janeiro Games in a thrilling battle. The American wagged her finger at the Russian there and also called her a drug cheat.
Now, the 20-year-old King is after a first world titlehere at the Duna Arena and looks in good shape after posting one minute 05.20 seconds, the fastest time in preliminaries.
Efimova was eighth before the turn in her heat before powering her way past Lithuanian rival Ruta Meilutyte, the London 2012 Olympic champion.
"I'm always really nervous in my first swim, but I took it easy and was able to bring it home," said King.
Talking of her outspoken comments about Efimova in Rio, she added: "I've always been a pretty honest person and not being myself in interviews is kind of hard. I'm just being me, just doing my own thing."
Efimova, the reigning world champion, qualified 0.40sec behind King and both will be separate semi-finals.
The morning after China's Sun Yang won the first gold medal of the championships in the 400m freestyle, the 25-year-old looked far from sluggish in leading the way in the 200m freestyle heats, clocking 1min 45.62sec, ahead of defending champion, Britain's James Guy.
Katie Ledecky, of the United States, looked just as smooth in booking her place in the 1500m freestyle final.
Ledecky, who won 400m gold on Monday, clearly had more to offer as she recorded 15min 47.54sec. The 2015 champion's rivals have yet to post under 16 minutes this year.
Later on Monday, Sarah Sjostrom of Sweden could set her second world record in 24 hours when she lines up in the women's 100m butterfly final.
The Swedish star set a world record for the 100m freestyle in her lead off leg in the women's 4 x 100m freestyle on Sunday night.
(Writing by Rod Gilmour; Editing by Ian Chadband)