Nervous Horton sets up showdown with Sun

Budapest - Horton dethroned Sun as Olympic champion over 400m at last year's Rio Games

Olympic champion Mack Horton set up a showdown with Chinese superstar Sun Yang on Sunday after the Australian squeezed through the heats into the men's 400m freestyle final at the world aquatic championships.
Horton dethroned Sun as Olympic champion over 400m at last year's Rio Games, branding the Chinese superstar a "drugs cheat" for serving a three-month doping ban in 2014 after taking a stimulant.
The pair will lock horns at the worlds in Budapest, but neither were fastest in the morning heats.
Austria's Felix Aubock clocked three minutes, 44.19 seconds with Sun second fastest at 0.36secs behind with Horton fifth fastest, at 1.41 back, of the eight finalists.
"I felt OK in the morning and I took the heats as a warm-up. I will try my best in the final but I did not set any goal for the evening," said Sun.
Horton admitted he had a few nervous moments after finishing third in his heat, but did enough to secure a berth in the final.
"The plan was just to make the final. You usually go for the top two, so when I was third, I was a little bit worried, but it was ok," admitted Horton. "I feel pretty relaxed, you always feel better when you get the first one out of the way and blow out the cobwebs.
"I just need to go faster tonight."
On Friday, Horton described his clash with Sun as "a rivalry between elite athletes and athletes who have tested positive", but was more reserved after the heats, simply saying "everyone knows how I feel about that".
The USA's gold-medal machine Katie Ledecky could lower her own world record in the women's 400m freestyle final on Sunday evening.
The 20-year-old broke her own championships record, set two years ago in Rio, when she clocked three min, 59.06 secs in the heats.
Her time was three seconds slower than the world record she set in Rio last year, but Ledecky says there is more to come.
"It's good to get the first one out of the way, but I feel like I have more for tonight," said Ledecky.
"I've worked towards this meet all year, I'm just trying to put it all together now."
Ledecky will compete in six freestyle events in Budapest and races twice on Sunday evening.