Swimming-Canada's McIntosh aces her 'biggest' night of world championships

July 27 (Reuters) - Canadian Summer McIntosh was delighted to have made it through what she described as her toughest night at the world championships with a gold medal, saying her dominant showing on Sunday boded well for the remainder of the competition.

McIntosh claimed gold in the women's 400 metres freestyle in three minutes and 56.26 seconds, nearly two seconds ahead of Chinese silver medallist Li Bingjie, with American great Katie Ledecky finishing in third place.

The three-times Olympic champion did not have much time to savour her win, however, and exited quickly to prepare for the 200 individual medley (IM) semi-finals.

Despite the tight schedule McIntosh was again in a class of her own, qualifying for the final more than a second ahead of her nearest rival.

"While preparing mentally for this world championships, I thought tonight is my biggest night of the whole meet," the 18-year-old said. "So to come out with a gold medal and a really good, strong semi-final in the 200 IM, I'm really happy.

"I've never done a double like that, and I think 400m free, at past world championships and Olympics, I haven't been at my best, and I haven't been where I wanted to be.

"To finally stand in the centre of the podium is promising for the rest of the meet... I was very relaxed, just based off how I've been feeling this past couple of months, and especially in warm-up today, I felt really strong."

McIntosh is coming into the competition on the back of a barnstorming Canadian trials last month, where she set world records in the 400 freestyle as well as the 200 IM and 400 IM.

"I'm in the best shape of my life," she said. "So now I just have to act on that and put it into all my races."