Alastair Cook celebrated his first morning as England's Test captain with an unbeaten fifty as the tourists moved to 104 for one at lunch on day one of the first Test against Bangladesh.

After being surprisingly inserted by Shakib Al Hasan, Cook was in assured form from the off and ended the session 55 not out.

Fellow opener Michael Carberry (30), one of two England debutants on display alongside 20-year-old seamer Steven Finn, was the man out on his international bow, falling leg before wicket after a flurry of early boundaries.

Carberry eased his nerves by tucking his third ball off his pads for two to register his first international runs.

Cook, who is now the 79th man to lead England in Tests, comfortably survived a hopeful appeal for caught behind off Shahadat Hossain in the second over.

Carberry found his stride as early as the fourth over, despatching Rubel Hossain for three fours in six balls, the third an imperious straight drive.

Two more boundaries followed for the Hampshire opener, both off the outside edge, as the home seamers began to leak early runs.

But he eventually fell to Mahmudullah, who won a straightforward lbw verdict as Carberry missed a sweep.