BUDAPEST, July 23 — Olympic champion Mack Horton set up a showdown with Chinese superstar Sun Yang today after the Australian squeezed 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” after his three-month doping ban in 2014. 

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”.

Ledecky, Peaty blast out

The USA’s gold-medal machine Katie Ledecky could lower her own world record in the women’s 400m freestyle final this 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 this evening.

After the 400m final, she will join the USA’s 4x100m freestyle relay squad, who were the fastest into the final.

Great Britain’s Olympic breaststroke champion Adam Peaty came within a whisker of his own championships record as the fastest into today’s 100m semi-finals with 58.21secs, just ahead of Cody Miller and Kevin Cordes of the USA.

Peaty is looking to lower his world record of 57.13secs set in Rio last year.

"It was a lot faster than I’ve normally been in heats, so it’s looking very promising,” said Peaty.

"Personally, it’s how far can I take my body.” 

Elsewhere, Sarah Sjostrom, the defending world and Olympic champion, was the fastest into this evening’s semi-finals of the women’s 100m butterfly.

Sweden’s Sjostrom clocked 55.96secs — half a second slower than her world record set last year at the Rio Olympics — with Kelsi Worrell of the USA and Australia’s Emma McKeon, the next fastest qualifiers.

Home-crowd favourite and Hungary’s ‘Iron Lady’ Katinka Hosszu blasted her way into the women’s 200m individual medley final tomorrow.

The world record holder clocked the fastest time of two mins, 07.49 secs — more than two seconds faster than her nearest rival. — AFP