Praveen Jayawickrama is essentially Sri Lanka's fourth-choice left-arm spinner. If Lasith Embuldeniya or Duvindu Tillakaratne had been fit, or if Prabath Jayasuriya had passed a fitness test, he would have struggled to find a place in the squad. But such are the manic, dramatic turns that both engulf and somehow also enliven the island's cricket, Jayawickrama took 6 for 92 to become Sri Lanka's most-successful bowler on debut, surprising everyone, but also, in a sense, no one.

See, this is the Test team that loses most of its pace attack and has its captain sacked, before going to South Africa and becoming the first Asian side to clinch a series there; the team that collapses twice at home to modest England spin, then defies a decent pace attack and the Dukes ball in the Caribbean; which has a batter with 11 Test hundreds and an average of almost 40 failing to make the XI, while an opener with an average of 26.31 after 41 Tests sits second on the year's run-scoring list; whose coaches are forever in peril; whose administration has been dominated by the same smarmy figures for 25 years; and yet whose cricket refuses to die quietly, though the situation has often seemed terminal.

Jayawickrama's personal journey is one of steady progress. He would tell his mother that he'd play for Sri Lanka one day at age eight, long before he even took the sport up seriously. He'd rise through the ranks at his school in Kalutara, before being offered a scholarship by a bigger one in Moratuwa in his senior years. He'd make the Sri Lanka Under-19 side, and become a leading bowler in one-dayers in particular.

But then in making the Test team, and producing this bowling performance, claiming the biggest opposition wickets as he did, Jayawickrama has become the latest partaker in Sri Lankan mayhem. There are only 10 first-class matches on his log book, and somehow, he is already a record-breaking Test bowler. Where Wanindu Hasaranga has been groomed for over a year, and Lakshan Sandakan for several more, Jayawickrama has leapfrogged both and collected better innings figures than either have ever managed.

There was no great magic to what he did on Saturday. In his own words, he kept the bowling tight, continued to probe, and had help from the surface, which in its own way has contributed to the chaos in becoming spin-friendly so rapidly, almost overnight. He put good revolutions of the ball, but suggested he was more a disciple of flight and subtlety, than of rapid, rasping turn.

Crucially, though, Jayawickrama did not allow Bangladesh's big-name aggressive batters to bully him off his lines and lengths. Tamim Iqbal lap-swept the first Jayawickrama ball he faced for four, then bashed consecutive boundaries off him next over. But there was no retreating to flatter deliveries, or faster darts. Jayawickrama continued to give the ball air, unperturbed by a batter who was racing at close to a run-a-ball in the first session. By the time Jayawickrama eventually got Tamim out, having him caught at slip with his second delivery to him from around the wicket, Jayawickrama was the frontline bowler Tamim had been most reticent against - his strike rate only 53.

"What I wanted to do in this match was bowl a lot of dot balls and build pressure," Jayawickrama said. "My favourite wicket was Tamim's - I had really wanted that one. I had bowled a lot of balls over the wicket, but he wasn't playing that many attacking shots to me. So the captain and a few of the senior players asked me to make a change and try it, and I'm very happy it worked."

Mostly, he got his wickets with deliveries that turned more than batters expected - one right-hander caught at slip, another at gully, before Mehidy Hasan was struck in front by a delivery he expected to go on with the arm. But he had Mushfiqur Rahim lbw with a straighter one too. If you're testing both edges, signs are, you're a left-arm spinner.

But these are signs only. At this venue in 2016, Kusal Mendis played one of Sri Lanka's greatest innings ever to turn a match against Australia on its head, and five years later cannot find a place in the national team. In that same match, Sandakan took 7 for 107 and has not replicated such success since. The tornado that is Sri Lankan cricket raises you up to dizzying heights occasionally; but for some, harrowing descents can follow.

All we can hope for 22-year-old Jayawickrama is that his landings are soft, and his cricket resilient. And that with time, he finds his place in the whirl.

Andrew Fidel Fernando is ESPNcricinfo's Sri Lanka correspondent. @afidelf