There were oohs and aahs, along with a bit of head-holding, in almost every over bowled by Mustafizur Rahman on the fourth day, especially in the second session. And not only from the slip cordon but also from people in the stands, the press box, and in all likelihood from those watching on TV too.

Kusal Mendis pressed forward to drive, but saw the ball wobbling around and played it softly. He resisted the temptation to drive off the next delivery too, and left the third outside off as well. Another defence and a leave followed, and one ball remained in the 45th over from Mustafizur. The last delivery came into the right-hander with the angle from around the wicket before curving away ever so slightly. Mendis played at it.

The wicketkeeper and the slip cordon appealed, but there was nothing more than a polite inquiry from Mustafizur. The umpire said not out and, after Bangladesh reviewed, replays suggested nothing decisive. But the TV umpire heard a noise as ball passed bat and overturned the decision. Mendis was unhappy on his walk back and Mustafizur had given Bangladesh a big breakthrough.

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Mashrafe Mortaza says a captain doesn't need to be in Mustafizur's ears all the time because he believes it could affect the bowler's thinking. For someone who has a bagful of tricks, Mustafizur uses variations quite tactfully, but things haven't been as smooth as they were before a shoulder surgery in August last year.

The Mustafizur who burst through against India in 2015 wasn't to be found in New Zealand, and the team management gave him a break after he complained he wasn't feeling fine. There were whispers that 'IPL fever' had got to him, with the T20 tournament slated to begin in the first week of April. It was all hearsay.

After Mustafizur was essentially dropped for the one-off Test in India in February, he played two first-class games and took four wickets. One umpire remarked that the batsmen had found it tough to negotiate Mustafizur's pace, a trait he isn't known for. Was he ready for another tour?

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During the first Test in Galle, Mustafizur showed glimpses of the bowler he was when he first emerged in 2015. But in these times the opposition sorts you out quickly. He finished his first Test in 18 months with three wickets, but bowled a late spell that may have gone unnoticed. The pace wasn't striking because he had found his groove through his delivery stride, pivot and release to bowl his cutters.

Here at the P Sara, Mustafizur's run-up looked less ginger, his action less hesitant, and his delivery stride more powerful. Most indicators signalled a return to form. All he needed was a performance.

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After taking Mendis' wicket, Mustafizur kept forcing Dimuth Karunaratne and Dinesh Chandimal to drive by bowling full and straight. Chandimal was sucked into one and was caught behind, reward for pressure that had been built up through the spell.

He bowled even better to Asela Gunaratne, but Shakib Al Hasan reaped the reward at the other end. Dhananjaya de Silva looked to play Mustafizur on reputation and gave him respect, but fell to the drive anyway, perhaps because he was caught in two minds.

Mustafizur's spell read 7-1-24-3, and it was as effective as it was fun to watch. He literally made the ball dash around like a yo-yo. Even more astonishing was the manner in which he got the ball to reverse, a factor that could be key on the final day against a lower order that will have to start from scratch.

Another effective, and fun, Mustafizur spell could be the difference between a fairly comfortable chase and a nervous one.