Hasan Mahmud took two wickets to reduce Australia to 51-2 at tea on the third day of the first Test in Darwin on Saturday, still 177 runs from making Bangladesh bat again.

Hasan, who took a career-best 6-55 in the first innings, claimed openers Jake Weatherald (0) and Travis Head (17) in identical fashion, chopping on to their stumps.

At the break Marnus Labuschagne was on 21 and Steve Smith eight.

Earlier, Mehidy Hasan Miraz scored a valuable half-century as Bangladesh were finally dismissed for 426 in their first innings just after lunch, a lead of 228.

After Bangladesh were well beaten by a Cricket Australia XI in their only warm-up match, including being bowled out for 54 in the second innings, many expected this Test to be an easy Australia victory.

But the unfancied visitors bowled the hosts out for 198 on the first day and then showed great dedication with the bat to keep the home side in the field for 138 overs.

Mehidy shielded the lower order brilliantly in the morning session to frustrate a tiring Australian attack.

When he was finally dismissed for 65 by Josh Hazlewood shortly after lunch, he had helped put his team into a strong position halfway through the match.

After Bangladesh resumed the day on 351-6, fast bowler Hazlewood took two wickets in the first hour to give the hosts hope of wrapping up the tail relatively quickly.

But Mehidy's outstanding batting allowed Bangladesh to defy the Australian bowlers on a typically hot and humid Darwin morning.

They were helped by some poor Australian catching, including an almost inexplicable miss by Smith, who got under a mistimed pull from Taskin Ahmed in the deep but dropped the simplest of chances.

Two balls later Mehidy miscued a pull shot only for a diving Head to spill a more difficult chance.

After defying the Australians for over an hour in the final session Friday, Hasan lasted just four overs of the first session Saturday before being trapped leg before by Hazlewood, adding one run to his overnight score of 13.

Taijul Islam made a breezy 17 before becoming Hazlewood's 299th wicket in Tests when he guided a ball straight to Cameron Green at gully.