Gary Ballance hit a career-best one-day score of 139 as Yorkshire Vikings completed a 32-run win over the Unicorns in the Yorkshire Bank 40 at Headingley.
It was just the sort of warm-up that Ballance wanted ahead of England Lions' two-day encounter against Australia from Friday, and his two other county colleagues in the Lions squad also enjoyed an outstanding match.
Alex Lees scored 63 off 74 balls and put on 134 in 23 overs with Ballance, who was later joined in a frenzied stand of 76 in only 35 balls with Liam Plunkett.
Off-spinner Jack Leaning then contributed with the ball with an astonishing return of 5-22 off four overs.
The Unicorns, who had a worthy century-maker of their own in Matt Lineker, were set 267 to win the Group C clash but were eventually out for 234 in 38.2 overs.
Yorkshire made a poor start with captain Andrew Gale and Dan Hodgson falling early.
Lees and Ballance soon mastered the situation and began to score freely. Both batsmen reached their half-centuries in the same over from Garry Park that the hundred partnership was raised.
Park eventually made the breakthrough by trapping Lees lbw, with Adam Lyth and Jack Leaning soon following.
That made it 185 for five in the 34th over but Ballance and Plunkett suddenly unleashed a torrent of strokes which kept the scoreboard constantly on the move.
Ballance hit Dominic Reed for 17 and 24 in successive overs. During this barrage, the unfortunate Reed saw Ballance dropped off a skier to Luke Beaven at square-leg soon after completing three figures, the first Yorkshire player to achieve the feat in the YB40 this season.
Ballance was eventually dismissed by Beaven off the final ball of the innings but he had helped Yorkshire to 266 for six, their highest score of the season.
Tom Lancefield and Lineker put on 77 for the first wicket before Lancefield was caught behind for 39 off Plunkett.
While the stylish Lineker was still there Unicorns were always in with a chance and he reached his fifty off 56 balls with five fours.
At the 30-over stage they were 176 for four, compared to Yorkshire's 169 for three, but Lewis Hill was caught hitting out at Plunkett.
Lineker completed his century but soon fell to Leaning for 107, who followed it up by getting rid of Keith Parsons, Beaven and Aneurin Norman to complete his five-wicket haul.