Budapest (AFP) - American Hunter Armstrong was awarded the world title after his training buddy Justin Ress was disqualified after finishing first in the men's 50m backstroke final in Budapest on Saturday.
The 21-year-old winner was downbeat after hearing he had won.
"It's really tough," he said."On the one hand I'm really happy we did it together but I wanted to share the podium together."
In the first of seven finals on the last night at the World Championships, the 24-year-old Ress touched the wall 0.02 seconds ahead of world record holder Armstrong.
After a video review, Ress was disqualified for finishing the race with his entire body under water.
The decision gave Armstrong victory in 24.14 seconds.
Ksawery Masiuk, a 17-year-old Pole, took silver, 0.35sec back, with Italian Thomas Ceccon, who set a 100m backstroke world record on Monday, inheriting bronze.
Armstrong wiped a tear away as he stepped off the podium after sheepishly accepting the gold which he said he hoped to give away.
"I'm very disappointed my team-mate was disqualified and hopefully Team USA's protest will be successful," he said.
Italian Gregorio Paltrinieri swum the second fastest time in men's 1500m freestyle history as he surged away to win his third gold in the event.
Paltrinieri had qualified only seventh fastest which meant he swum in lane one, out of the eyeline of favourite Florian Wellbrock in lane four.
The 27-year-old Italian surged away from the start, setting a breakneck pace.He led from the 100m mark until the end.He was on world record pace for much of the race before fading at the end to finish in 14min 32.80sec and miss Sun Yang's mark by 1.78sec.
American Bobby Finke was second, 3.90sec back, with Wellbrock third at 4.14.
Asked about what his tactics were, he replied: "I have no idea.The plan was try to win this race."
Lithuanian Ruta Meilutyte won her first world gold since 2013 when she edged Italian 17-year-old Benedetta Pilato by 0.10sec in the women's 50m breaststroke final.South African Lara van Niekerk was third.
Meilutyte had not when a major championship medal of any colour since 2015.
"It's nice to be a world champion," she said.
Pilato had won the 100m race on Monday.
