Lancashire 170 for 6 (Vilas 43) beat Yorkshire 161 for 9 (Pooran 43, Mahmood 3-33) by nine runs

A Roses T20 tie on an impossibly sultry Headingley evening with temperatures still close to 30C: Britain's second hottest day on record was a draining accompaniment to a raucous Blast tie that generally combusts of its own accord and it was Lancashire who confirmed themselves as one of the powerhouses of the North Group with a nine-run win.

Three successive Roses T20 wins have given Lancashire bragging rights over their Pennines rivals and, on this evidence, they will remain garrulous all summer. Perhaps the dismal rail service across the tops is a consolation for the Tykes after all, as it keeps their rivals well out of earshot.

Lancashire, under the experienced leadership of Dane Vilas, once again looked to be a well-drilled, knowledgeable side, potential tournament winners. Yorkshire, despite a sterling effort from West Indian Nicholas Pooran to turn the game in their favour, now have one win in four and are still struggling to find a convincing blend.

Pooran is now four matches into his five-game stay. He endeavoured to shoulder responsibility for Yorkshire's pursuit of 171. He came in at 78 for 3 in the ninth over, replacing David Willey, who hobbled off after his pumped-up 32 from 25 balls had come to grief with a slog sweep to deep square. He soon lost Harry Brook, for 30, wised-out by Richard Gleeson who hammered one in short to outdo his foray down the pitch.

A prodigious backswing saw Pooran bully three leg-side sixes off the otherwise parsimonious legspinner Matt Parkinson with a destructive grace that spoke of his talent, but he was sixth out, bowled by Saqib Mahmood as he made room, leaving Yorkshire 31 short with 16 balls remaining. To all intents and purposes their hopes left with him.

Pooran's departure was a relief for Steven Croft, who had dropped him off Richard Gleeson on 8, pedalling back for a catch at long off. Croft, normally so reliable, got it in the neck, and then got it in the neck some more from the bulk of an 18,500 crowd.

But it was Mahmood, looking every inch a bowler of international pedigree if only, at 22, he can stay fit, who had most cause for delight as he returned 3 for 33 under considerable pressure. He had Dom Bess lbw for nought two balls later and when Jordan Thompson cut the requirement to 11 from three balls by squeezing a boundary through Maxwell's hands at long off, he closed the game out with a couple of 90mph yorkers.

There is data on everything these days, but not much, one will wager, on how Headingley pitches play on a parched night when ice cream melts in seconds, rivulets of sweat run off the most static spectator and Vinny the Viking, the Yorkshire mascot, deserved a hardship payment. It was at its most soporific - wasn't everybody - and did not concede a half-century all night, but Lancashire batted with intent from the outset, buoyed by the surprise return of Liam Livingstone from an intercostal injury.

Lancashire must have had their sights on 200 when Vilas and Glenn Maxwell were assembling a fourth-wicket partnership of 61 from 33 balls for the fourth wicket. If they had achieved that, they would have been unassailable. But both fell in quick succession and the final charge was left in the hands of Josh Bohannan and Keaton Jennings who both looked underpowered for the task and mustered only 28 from 27 balls between them and survived a couple of run-out opportunities and a dropped catch in the process.

Maxwell was overshadowed by Vilas, who has started the Blast season in excellent form. Nevertheless, Duanne Oliver's intervention when Maxwell had made 25 from 18 balls was an important one. It will be no surprise for regular observers of Olivier that he tried a bouncer, a quick one too, which Maxwell could only glove to the wicketkeeper as he became all of a tangle shifting to the offside.

As far as Yorkshire were concerned, there was personal satisfaction for Jack Shutt, a 22-year-old offspinner from Barnsley, who only learned shortly before the start that he was making his debut as a replacement for Josh Poysden, who will miss the tournament because of concussion after a fractured skull bowling in the nets

Shutt had only bowled twice in senior matches since May 28, recording 0 for 64 in a couple of 2nd XI Championship matches, but he maintained a blockhole length with intelligent changes of pace and flight and was rewarded as Steven Croft (reaching forward to Shutt's third ball, a low full toss) and Livingstone mishit to long on and long off respectively in his first two overs.

His success was striking enough for Yorkshire to limit his fellow offspinner, Bess, to a solitary over, and that, incidentally, in the Powerplay: spin in the opening six overs is a tactic used only rarely by Yorkshire in the Blast. But Yorkshire's young captain, Tom Kohler-Cadmore, a "temporary" stand-in for Steve Patterson, must wonder how to rev up a side that packs all its threat into the top order and which will soon be further weakened by Pooran's departure.