Australia's Jason Gillespie smashed the record for the highest run-scoring nightwatchman on Wednesday, cracking a career-best 201 on the fourth morning of the second Test against Bangladesh in Chittagong.

The fast bowler celebrated his 31st birthday in style, shattering the previous Test record of 105 set by compatriot Tony Mann in December 1977 against India.

Australia declared their innings closed on 581 for 4 just after the lunch break when Gillespie completed his unbeaten double century, taking a lead of 384.

Starting the day on 102, Gillespie drove a delivery off spinner Abdur Razzak to the long off boundary to overhaul Mann's record. He finally reached his double century by driving a delivery from Bangladesh spinner Mohammad Rafique through fine leg.

Gillespie's previous highest Test score had been 54 not out against New Zealand.

He faced 425 balls in his marathon innings, and occupied the crease for 576 minutes.