Worcestershire 179 for 5 (Wessels 91) beat Yorkshire 177 for 7 (Lyth 68) by five wickets
Worcestershire recovered from early strife with the ball before Riki Wessels mixed power with a touch of invention in a superb 91 as Yorkshire, defending 178, were ultimately brushed aside by five wickets with 15 balls to spare at Emerald Headingley.
The Vikings lost their third game in six and will rue not making the most of being 104 without loss in the 12th over.
Their 177 for 7 looked competitive, but they should have been closer to 200 after openers Adam Lyth and Tom Kohler-Cadmore laid the platform with a century partnership having elected to bat.
In reply, Rapids opener Wessels made the chase towards a fourth win from six North Group games look a routine one with 10 fours and five sixes in 51 balls.
Lyth top-scored and hit four sixes in 48 balls, sharing 104 for the first wicket with ex-Worcestershire player Kohler-Cadmore, who hit two sixes.
They shared their second century opening stand of this season's Blast and took the visitors' seamers to task on an excellent Headingley surface.
Lyth hit successive sixes off Wayne Parnell and Pat Brown in the second and fourth overs en route to a 32-ball fifty. He was particularly strong square on both sides of the wicket, while Kohler-Cadmore was more measured, hitting nicely on the up down the ground and over cover.
But they were two of seven wickets to fall inside the last nine overs of an innings which fell away to devastating effect.
Both fell caught at deep mid-wicket off the off-spin of George Rhodes. That Rhodes - who finished with 2 for 12 - only bowled two overs was a surprise, especially with none of Worcester's five seamers going at less than eight an over. They were the only two overs of spin in the innings.
That said, their seamers did hit back with effect. Dillon Pennington removed Harry Brook and David Willey in the 16th over, leaving the score at 140 for four, just when they were looking to launch. And Brown also struck twice at the death.
Worcestershire made a bright start to their chase as Wessels took the lead role.
When Martin Guptill top-edged a short ball from Duanne Olivier to short fine leg, they were 28 for 1 in the fourth over, and well on the way to a powerplay score of 47 for one after six overs. Wessels had 26 of them.
But in the next over, bowled by returning Vikings captain Steve Patterson after a five-game rest, Wessels launched sixes over long-off and long-leg as 20 runs came off it.
Wessels reached his second fifty of this season's Blast off 32 balls, but not before he lost Callum Ferguson caught at backward point off Lyth's off-spin as the score fell to 93 for two in the 10th.
When he fell in the 15th over, caught at long-on off Dom Bess' off-spin, the damage had been done with the score at 152 for 3and only 26 more needed.
Olivier and David Willey claimed the consolatory wickets of Parnell (27) and Ross Whiteley late on, but it proved too little, too late, as Worcestershire stayed second in the North Group, still just a point behind Lancashire.
