Hannah Miley held off Olympic champion Ye Shiwen to claim Great Britain's first gold medal of the World Short-Course Championships when she won the 400 metres individual medley in Istanbul last night.

Ye grabbed the imagination and the gold medal at the Olympics this summer, her freestyle leg en route to victory in the eight-length event almost defying belief. The Chinese teenager was so impressive in London that she finished just three hundredths of a second slower over the final 100m than Ryan Lochte, winner of the men's race. Indeed, her last length was faster than four of those contesting the men's final, including Lochte and Thiago Pereira, the gold and silver medallists.

Miley, who was fifth in London, had qualified fastest into the final in Istanbul, but predicted it would be a different race in the final, claiming that Shiwen had been "playing" in the heats.

She appeared to be right but, after settling into fourth place after the butterfly and backstroke legs, Miley then produced a superb breaststroke to move ahead of the field going into the freestyle, a full 2.04 seconds ahead of Ye. The Chinese came back in the final length – completed in 28.14 secs, the only sub 29-second last length in the field – but Miley held her off by 0.19s to win in a new championship record of four minutes 23.14 seconds. The time is the fastest ever in a textile suit, bettering her own mark from the European titles last month.

The 23-year-old later admitted that she "was hanging on for dear life" and said the achievement had significance for both her and her father and coach Patrick, vindicating their approach after the Olympics. "A lot of top athletes aren't here so I see it as an opportunity, and any opportunity I see I try and take it," said the Scot, who then swam the fastest British leg as the 4x200m freestyle relay team finished in fifth.

"I was aiming for it to be a confidence booster for both myself and my dad and what we are doing this season. Not only were we trying to chase placings, but also to do a really good time.

"But the main thing is long-course [50m] swimming. I am really happy with what I've done but I am not going to be [truly] happy with it until I can prove I can do it long-course as well. Hindsight is a great thing and lots of people have cliches, but I probably wouldn't be the athlete I am today doing those times if the Olympics hadn't happened."

Miley's was the second British medal of the night after Jemma Lowe finished third in the 200m butterfly. The 22-year-old was sixth at the Olympics in the summer, but has a good short-course record having finished second at the last 25m worlds in Dubai two years ago.

Seventh fastest into the final, the Swansea ITC swimmer was unaffected by swimming from lane one, despite being unaware of what the expected medal contenders were doing in the lanes next to her. She led at the 150m mark and, although she was overtaken by Hungarian Katinka Hosszu and 2012 Olympic champion Jiao Liuyang, she broke her own British record with a time of 2mins 3.19secs to claim bronze.

"I'm really pleased with that. I didn't know what to expect after this morning when I was in that slow heat by myself and I just scraped into the final," said Lowe.

"Because I have won a medal previously at world short course I was really determined to get up there so I just gave it my very best tonight and I can't believe how it worked out."

There was no such satisfaction for Michael Jamieson, the Olympic 200m breaststroke silver medallist. The Glaswegian set a personal best of 58.56 in the 100m breaststroke but was left frustrated as it only proved good enough for 12th.

"It's the same old story on the 100, I just can't keep up with the bigger guys," said the Scot. "It's frustrating, it's the fastest I have ever been but I am getting to the stage with the 200m that if I am ever going to improve then my 100 needs to come down."

That was in contrast to Georgia Davies, another Swansea ITC swimmer, who set a personal best of 57.41 to qualify third for the 100m backstroke final. Lizzie Simmonds was 10th in 58.34, although her focus is on the 200m since her move to Bath ITC.

The United States enjoyed a highly successful start to the meet with three gold medals; 11-time Olympic champion Ryan Lochte taking two, in the 200m freestyle and the 4x100m freestyle relay. The USA women won the 4x200m relay.