Junaid Siddique and Mushfiqur Rahim did everything that could have been asked of them in extending Bangladesh's resistance into the fifth day of the first Test, as they dourly thwarted a medley of pace, spin and part-time bowlers for 37 overs and two-and-a-half hours, to heighten England's frustration on another steaming hot day in Chittagong. However, both men know that their greatest challenge could be lurking just round the corner, as England prepare to get their hands on the second new ball.

The ball is now 75 overs old, and to judge by the lack of assistance they extracted after tea (the odd hint of reverse-swing notwithstanding) England are ready to fling it far out into the Bay of Bengal, and instead revert to the pacy, bouncy line of attack that caused such havoc in Bangladesh's top order in the first innings. In Stuart Broad, Tim Bresnan and, especially, the 6'7" Steven Finn, England's attack is lankier than anything the Bangladeshi batsmen are used to encountering.

"We've been building pressure by going past the bat, but the new ball will be a different kettle of fish," said Finn, who impressed with his discipline in his second innings as a Test cricketer, even if he did not have the figures to show for his efforts. "It will be a harder ball which will bounce more, and that's something the Bangladeshi batsmen have struggled with so far in this Test match. Broad and Bresnan opened the bowling and caused problems for them, and we'll be looking to exploit that tomorrow."

And yet, the efforts of Junaid and Mushfiqur proved once again the fight and tenacity in an ever-improving Bangladeshi outfit. For Mushfiqur, his unbeaten 47 was merely a continuation of the form and focus he had shown in his first-innings 79, when only an exceptional catch from James Tredwell could prise him from the crease. As Graeme Swann noted after the third day's play, his five-foot-nothing frame proved adept at disrupting the lengths of all the bowlers, as naturally good-length deliveries became long-hops, and yorkers turned into half-volleys.

The real surprise package, however, was Junaid, whose place in the side had been under serious scrutiny following a limp first-innings dismissal, when he and Imrul Kayes had been bullied from the crease by Broad's rib-tickling bouncers. This time, however, he fought against his natural instincts, as he ground his way to an unbeaten 68 from 199 deliveries, which is already the longest he has batted in a Test-match innings.

"I had a commitment within myself," said Junaid. "I was practicing against the short ball, but it can't be changed overnight, so I tried to fight with my strengths. The planning was to stay at the crease for a long period. It was a hot day, and in our conditions I believed that if I can survive a little while, it could be a problem for them.

"I think I have gained some experience after playing a long innings, and that has given me confidence," he added. "I was lacking in confidence recently, and because of that it was not only short balls but also half-volleys that were getting me out. But I've been working hard on my technique in the nets, and we're getting more used to facing tall players, such as Morne Morkel from South Africa."

But after a duck in his only appearance in the ODIs, and an indifferent performance for Bangladesh A last week, Junaid was in need of a score to preserve his place for the Dhaka Test. However, he did a good job of putting such thoughts to one side. "Every innings is important for a cricketer, so I never thought in this way," he said. "Of course I needed some runs, and also it was needed for the team, but I never plan early. I always set my plan after going to the wicket. We were just enjoying our game, and trying to support each other, and hoping to see off the day."

Meanwhile, Finn did a good job of disguising any mounting frustration within the England camp. "At no stage did we sit back and say we were going to finish this game today," he said. "We just want to bowl as many dot balls as possible, and build pressure on Bangladesh, because that will get us wickets. They aren't going to be walked over because they've got good batsmen, but if we bowl enough good deliveries, hopefully they'll get themselves out.

"They played very well," he added. "They didn't score many runs, but they didn't play any loose shots either. They didn't give any chances - there were a couple of lbw decisions that weren't given, but they probably weren't out either. The Bangladeshi batsmen played well, but we expected that. We knew that coming over here on their own turf, we were going to have to work hard to take their wickets."

It's still highly improbable that Bangladesh will escape with a draw, even with a reported threat of rain following two exceptionally humid days. But true to the spirit they have shown since Tamim Iqbal's counterattack towards the end of the second day, the underdogs are determined to keep nipping at England's heels, for as long as they possibly can.

"It would be nice if I could tell you the future," said Junaid. "We have already lost five wickets and their score is very high, but we will try to occupy the crease, and if we can get a good partnership then the positives will come out. Everybody has tried to stay at the crease since we had almost two days to bat, but we will just go session by session."