Bicester's Kieran Bird admitted he had surprised even himself as he got his British Championships assault off to a fantastic start with third place in the boy’s junior 400m freestyle final .

Tuesday saw the action get under way at the iconic London Aquatics Centre, the scene of the 2012 Olympic Games.

And the surroundings clearly spurred Bird on as he soared into the final by touching home in 4mins 4.08secs minutes in his morning’s heat.

But the Bicester Blue Fin starlet wasn’t done there, shaving almost four seconds off his time in the evening’s final to finish in 4.00.62 for third place.

Millfield’s Brodie Williams won the event in 3.58.05, ahead of Jamie O’Connor (Thanet Swim) in a time of 3.58.77.

“I was just feeling really good in the water and a lot better than what I did in the heat,” said Bird.

“But still, I didn’t expect to do as well as that.

“And I am really pleased because that was better than anything I could have expected before the race.

“I was up for it and feeling really good ahead of the race so that played its part, but even then I still didn’t think I would go as fast as I did.

“I was going into the race going for 4.03 or 4.02 as a time.

“So to take four seconds off my heat time is fantastic.”

Bird was due to take part in the 200m butterfly heats yesterday.

To keep up to date with all the action of the swimmers in the lead up to Rio follow British Swimming on Twitter Facebook or Instagram