An opening stand of 114 from Aneurin Donald and David Lloyd off 61 balls was not enough to help the Falcons emerge victorious at Headingley.
Yorkshire should have been pursuing many more, but the Falcons stuttered from 114 without loss at the start of the 11th over to 179 for six. Opener Aneurin Donald blasted a brilliant 84 off 41 and England’s Joe Root claimed two for 20 from three overs of off-spin.
Veteran opener Lyth top scored in the chase as Yorkshire continued their good start to the North Group.
Lyth was supported well by Dawid Malan in a 14.4-over opening stand of 137. The latter finished unbeaten on 79 off 48, sealing victory with 11 balls remaining.
Derbyshire, after thrashing rivals Notts Outlaws on Friday, raced away having been inserted, with Donald taking the lion’s share of 22 off Matthew Revis in the fifth over. He ended it with two fours and two leg-side sixes.
The Falcons finished the six-over powerplay at 70 without loss and put a much-changed Vikings attack under serious pressure.
The hosts are suffering from a number of seam bowling injuries and earlier this weekend announced the loan signing of Surrey quick Conor McKerr on a five-game deal. It was, therefore, a surprise when he was left out of this fixture.
Donald continued his assault at a notoriously batter-friendly venue. And ultimately, Derbyshire were under par as a result of the true conditions.
Fellow opener David Lloyd wasn’t quite the silent opening partner but not far off. When Derbyshire reached 100 in the ninth over, he had 30 to Donald’s 69.
Jordan Thompson had Lloyd caught at deep midwicket for 41 to make the initial breakthrough, Dom Bess bowled Wayne Madsen and Samit Patel was caught at short third off Matthew Revis – 131 for three in the 13th over.
Donald was starved of the strike and followed, caught at deep cover off debutant seamer Ben Cliff – his maiden wicket.
Ross Whiteley then hoisted Root to deep backward square-leg. The same bowler had Brooke Guest caught at deep midwicket in the last.
Derbyshire found or cleared the boundary 16 times in the first half of the innings but only four times in the second. It proved costly and best highlighted their struggles.
Lyth set about the chase like Donald where was similarly dominant against the new ball.
By the time he reached his fifty off 33 balls with three sixes, his 28th for Yorkshire, the Vikings were well on course at 82 without loss in the ninth over.
One of those sixes was handsomely hoisted over cover off Daryn Dupavillon’s seam.
The rest of Lyth’s four sixes were slog-swept or pulled leg-side, just as Malan did with two en-route to a fine fifty off 37 balls.
By the time Lyth was caught at long-off off Dupavillon, Yorkshire needed 43 and sealed victory in the 19th over.
“We were really pleased with the start we had, but between myself and Dai (Lloyd), we just started to lose momentum.
Batter Aneurin Donald said: “Once Dai got out, I tried to over-hit a little bit, and we just built that pressure on ourselves. No one really got going, and they executed their plans really well. But we left our bowlers 20 or 30 runs short, and Headingley’s very difficult to defend against a top-quality Yorkshire batting line-up.
“From where we were, there’s no doubt we should have got 200. It’s on me to see us through there, and the guys coming in lower down should have probably got off to a better start than they did.”
