The 22-year-old Pole – riding his first meeting since being handed the captaincy for a month – was in scintillating form as he racked up his first full 15-point maximum in Poole kevlars.
While plenty of the Wimborne Road faithful had been justifiably excited by Holder’s return in place of injured skipper Darcy Ward, ultimately it was Janowski that provided home fans with reason to cheer.
His exploits were courageously backed up by Kyle Newman, who totalled paid 13 from reserve as he continued where he left off against Eastbourne.
Pirates did not have it all their own way against a Bees septet that held the lead after heat nine and were only consigned to defeat with one race left.
A rapid gate enabled Ryan Fisher to lower Holder’s colours in the opener and spearhead a 4-2 alongside Hans Andersen.
Lee Smart blasted round the outside to join Josh Grajczonek for a 5-1 in heat two, only to pull up on the back straight with mechanical woes.
Janowski and fellow countryman Shamek Pawlicki were split by Kenneth Hansen before Vaclav Milik’s flyer was offset by more bike problems for Smart.
Janowski became the only rider to dip under the minute barrier as he and Holder blitzed Hansen and Kyle Howarth in heat five, putting the hosts 17-13 up.
Coventry reversed that display in the next outing thanks to Andersen and Chris Harris, with Milik and Pawlicki getting in each other’s way at the back.
A daredevil ride round the boards from Newman provided the heat of the evening as he went knee-to-knee in a thriller with Kyle Howarth.
Heat eight was a rollercoaster in which Pirates ended up on the receiving end of a maximum when Pawlicki hit a rut and fell, allowing Hansen and Fisher to fizz past.
Newman looked on a different level to his fellow reserves as he stormed to a third straight three-pointer in heat nine, allowing his team to reduce the advantage to 28-26.
Holder’s attempts to protect Grajczonek out front resulted in the 2012 world champion losing second place to Hansen, but Poole were still able to level matters.
The perfect run of Janowski continued into heat 11 despite the attentions of Howarth, who had come from third to first early on before the Pirates charger replied.
A textbook cutback from Grajczonek on Fisher won him heat 12 as Newman’s winning run finally came to an end.
Janowski looked extremely comfortable in heat 13 and then Milik and Newman made sure of victory in heat 14, with the latter seemingly propelled into second by the roar of the home faithful.
All three points were grabbed by the hosts thanks to Janowski’s gate-and-go victory in heat 15, capping a wonderful display from the ex-King’s Lynn man.
Meanwhile, Swindon have confirmed they have booked Kent’s Benji Compton to replace Steve Worrall at reserve for Good Friday’s double-header.
Pirates 49: 1 Chris Holder (2-2*-1-0-0) 5+1, 2 Josh Grajczonek (0-1-3-3) 7, 3 Shamek Pawlicki (1-0-f-1) 2, 4 Vaclav Milik (3-1-1-3) 8, 5 Maciej Janowski (3-3-3-3-3) 15, 6 Lee Smart (r-r-0) 0, 7 Kyle Newman (3-3-3-1-2*) 12+1. Team manager: Neil Middleditch.
Bees 41: 1 Hans Andersen (1-3-0-2-2) 8, 2 Ryan Fisher (3-2-2*-2) 9+1, 3 Kenneth Hansen (2-1-3-2-1*) 9+1 , 4 Kyle Howarth (0-2-2-1) 5, 5 Chris Harris (0-2*-0-1*) 3+2, 6 Jason Garrity (2-0-2-0) 4, 7 James Sarjeant (1*-1*-1*-0) 3+3. Team manager: Gary Havelock.
Ht 1: Fisher, Holder, Andersen, Grajczonek, 61.50 (2-4)
Ht 2 (re-run): Newman, Garrity, Sarjeant, Smart (retired), 61.66 (5-7)
Ht 3: Janowski, Hansen, Pawlicki, Harris, 60.18 (9-9)
Ht 4: Milik, Fisher, Sarjeant, Smart (retired), 60.34 (12-12)
Ht 5: Janowski, Holder, Hansen, Howarth, 59.75 (17-13)
Ht 6: Andersen, Harris, Milik, Pawlicki, 60.16 (18-18)
Ht 7: Newman, Howarth, Grajczonek, Garrity, 61.38 (22-20)
Ht 8: Hansen, Fisher, Milik, Pawlicki (fell), 61.22 (23-25)
Ht 9: Newman, Garrity, Sarjeant, Smart (retired), 61.94 (26-28)
Ht 10: Grajczonek, Hansen, Holder, Harris, 60.91 (30-30)
Ht 11: Janowski, Howarth, Pawlicki, Andersen, 60.90 (34-32)
Ht 12: Grajczonek, Fisher, Newman, Sarjeant, 61.32 (38-34)
Ht 13: Janowski, Andersen, Harris, Holder, 60.37 (41-37)
Ht 14: Milik, Newman, Howarth, Garrity, 60.75 (46-38)
Ht 15: Janowski, Andersen, Hansen, Holder, 60.84 (49-41)