Chambers keen to keep youngsters in check

Chambers, 31, eased to victory in his heat in 10.20 seconds as all his main rivals - including Simeon Williamson, Craig Pickering, Tyrone Edgar and Harry Aikines-Aryeetey - also comfortably advanced.

"It's just the heats, the most important thing is to get the first one out the way and get ready for tomorrow," said Chambers, who will also contest the 200m this weekend at Birmingham's Alexander Stadium.

"The World Championships have been high on my agenda from the start of the year so it's all about qualifying."

Williamson, who won his heat in 10.24secs, said earlier this week he thought a sub-10 second run would be necessary to win the 100m, with only the first across the line guaranteed a place on the team for Berlin next month.

Chambers won the same event last year in 10 seconds flat with Williamson just behind in 10.03, and Chambers added: "I know everyone wants to see a sub-10 but more importantly I know I have stiff competition so I need to keep cool as possible because these guys are a lot younger and more energetic than me.

"I am in shape, maybe for a repeat of last year, 10 seconds flat, or if the wind is right dip under. That would be nice.

"It's a good rivalry (with Williamson), keeps me on my toes. He is very excited about his chances against me but I don't want these young boys coming to beat me. Over 100m I'm definitely confident, that's my domain."

Chambers won the 100m and 200m for Britain at the recent European Team Championships in Portugal and admitted he does intend to double up in Berlin too.

"The timetable works very well in Berlin, there is a huge time gap between the 100 and 200m," added Chambers, who also won the European Indoor title in Turin in March. "We have worked hard towards it. This year I've had more races than I wanted but I had to take advantage of them. I would like to have run faster but each time I have raced I have won."