Hannah Miley had to settle for silver as Adam Peaty once again demonstrated his thirst for glory on the opening night of the European Championships in London.
Scot Miley finished second in the women's 400metres individual medley as Katinka Hosszu of Hungary won gold, while Peaty and Ross Murdoch advanced to the men's 100m breaststroke final in first and second place.
World record holder Peaty, who won the European title in 2014 and world gold last year, clocked 58.74 seconds in his semi-final, with Murdoch winning his semi-final in 59.67secs.
With August's Olympics in Rio in mind, the Britons are in heavy training throughout the championships, but Peaty was pleased with his "training swim".
The 21-year-old City of Derby swimmer said: "It didn't feel particularly great, but 58.7 is only 0.3 off the old world record (set by South Africa's Cameron van der Burgh in winning gold at London 2012).
"I'm in a good place right now. I can feel the strength on top of my stroke.
"I'm in full training, but I can still back up these 58s, which is a very good sign.
"It'd be nice to get a bit quicker (in Tuesday's final)."
Peaty will prioritise medals over times in a competition he described as good practice for Rio - and he may not even shave down for the final.
He added: "I'll see what my coach (Mel Marshall) says, but probably not. I think I was the only one in there unshaven."
Miley earned Britain's first medal of the championships in 4mins 35.27secs - two seconds behind the time set rested at April's British Championships in Glasgow, which doubled up as the Olympic trials.
Hosszu won in 4:30.90, while Aimee Willmott was fourth in 4:40.08.
Garioch's Miley, 26, said: "It is always hard coming into these championships when you are not 100 per cent fresh.
"Your ego gets bashed a bit because you want to swim fast but it is not as easy as if you were fresh, shaved and ready to race.
"It is a big confidence booster and it is nice to know that I am the second best in Europe.
"I was not expecting to do the time that I did at the trials. To get anywhere near that was a bonus and I was only just over two seconds (behind)."
James Guy, the world 400m silver medallist, was 27th after the morning heats and Gabriele Detti of Italy won the final in a championship record of 3:44.01. Stephen Milne was eighth in 3:49.49.
Guy clocked 3:52.91 - nine seconds adrift of his personal best - and attributed the performance to being in heavy training.
He also wore his traditional trunks and heavy stubble, while others were in their thigh-length competition suit and clean shaven.
"I'm just focusing on myself. All the main guys heading to Rio are working for that," said Guy, who was planning to return on Monday evening for a 5km training session.
"The first 200 felt all right but I felt a bit sick at 250m, 275m but I just got on with it.
"I knew it was going to be a hard swim. This is part of the training, that's it."
Guy, who won gold at the Kazan World Championships over 200m, races over four lengths on Tuesday, with the final on Wednesday, and in the 100m butterfly later this week.
Asked about Guy's swim, Peaty said: "He's going to smash up Rio and that's all that matters."
Chris Walker-Hebborn was 12th in the men's 100m backstroke, also missing out on the final.
There was the potential for better news on Tuesday - and not just from Peaty.
Fran Halsall was the fastest qualifier in advancing to the women's 50m butterfly final in 25.35 and Ben Proud progressed second quickest in the corresponding men's event, in 23.42.