KAZAN, Russia (AFP) - Ryan Lochte of the United States made history by winning his fourth straight 200m individual medley gold at the world swimming championships on Thursday.

Lochte clocked 1min 55.81sec with Brazil's Thiago Pereira taking silver at 0.84sec and China's Wang Shun picked up bronze at 1.00 dead.

The 31-year-old Lochte is the first swimmer to win the world 200m IM four times in a row and has now won 16 gold medals at world championships dating back to 2005.

Michael Phelps has won three consecutive 200m IM world titles, but Lochte has now taken the gold in this event at every world championships since Rome in 2009.

Grant Hackett is the only other swimmer to have won four consecutive world titles in a single event, having achieved the feat in the 1,500m freestyle between 1998 and 2005.

The 35-year-old Hackett is racing in the 4x200m freestyle relay for Australia in Kazan.

"It's an honour to go down in history with one of the world's great swimmers - Grant Hackett," said Lochte.

This is his 24th medal at his sixth world championships and his first in Kazan, but he struggled for an answer when asked if this was the biggest moment in his illustrious career.

"It would have to be a toss up between this, it's the coolest thing to make history in any sport, or 2011, when I broke the (200m IM) world record," he said.

"It's something I'll remember for the rest of my life."

PHENOMENAL

Lochte revealed a text message from US star Michael Phelps, who was suspended for Kazan after last year's drink-driving conviction, telling him to take leadership of the US team, had inspired him.

"Whenever Michael says anything to any swimmer you are going to take it to heart, because he's the world's great swimmer who ever lived," said Lochte.

"When he says you are the team's leader and you have to help those around you and he's right."

Lochte's victory sealed a good night in the Kazan pool for the US as Katie Ledecky claimed her fourth gold medal of these world championships by anchoring the women's 4x200m freestyle relay win.

"There's only one word I can use to describe Katie Ledecky - 'phenomenal'," said Lochte.

"It seems whenever she sets foot in the water she either wins gold or breaks a world record - she's a beast.

"She got Team USA on a roll and we have to carry on that momentum."

Lochte has fielded numerous questions in Kazan about his new style of turn when he kicks off the wall on his back, before flipping on to his stomach at the last minute.

"We might need to call this the 'Ryan Lochte Turn' because it's causing a buzz," he said with a grin.

"My coach and I pulled a lot of data in training and discovered I'm quicker if I turn on my back and then flip to my stomach.

"I'll keep doing it until I get disqualified, simple as that.

"I've only been working on it for the last three weeks. I pretty much had to get it down in our pre-worlds camp and where better to work on it than at a world championships - ooops."

Lochte enjoys star status whenever he races and regularly receives gifts from Russian fans here during these championships.

"I'm very humbled because I never thought swimming would make it this far," he said.

"I still can't believe I have fans and people who cheer for me. It shows that all the hard work you put in can pay off."