Worcestershire 241 for 7 (Clarke 56, Thornton 4-42) beat Warwickshire 304 for 5 (Bell 104, Clarke 84*) by three wickets (D/L method)
Ian Bell's first century for Warwickshire in 13 months was all in vain as his side went down to Worcestershire in a high-scoring North Group game in the Royal London One-day Cup at New Road.
Last year's tournament winners seemed to have thrown off the shackles by romping to 304 for 5 in a match reduced to 45 overs-a-side but their neighbours reached a revised target of 241 in 34 overs to win by three wickets under the Duckworth-Lewis method.
Bell said: "The hundred felt good but in a losing cause,it doesn't mean a great deal. Individual stuff is great, isn't it, but winning is what we are about, so it was has been tough for that.
"This was a great toss (for Worcestershire) to win. There was a lot of seam movement in that first 10 or 15 overs. We could been six down for not many. I thought Rikki Clarke was fantastic and we did well to get 300."
While Bell had many years as a top-drawer batsman for England, Worcestershire's Joe Clarke potentially has a similar career ahead of him and here he provided a glimpse of his ability with his first 50 of the season in any competition.
The 20-year put behind him a quiet start to the summer by hitting the first three balls he faced to the boundary and went on to transform the situation after Worcestershire had stumbled to 57 for 4 in the first nine overs.
While Clarke's driving was a feature in making 56 from 51 balls, the game-changer was wicketkeeper Ben Cox, who took a chunk out of the New Road stand facia with a six off Ateeq Javid in his dash to 49 from 41 balls.
Jeetan Patel ended a partnership of 81 in 11.3 overs when Cox was lbw, playing across a straight ball, but Worcestershire kept going with three sixes in John Hastings' 36 and a second maximum for Ross Whiteley (35 not out) in completing the win with 13 balls to spare.
Worcestershire return to second place in the North Group but Warwickshire are rooted to the bottom after losing six of their seven matches.
Young seamer Grant Thornton did his best to keep the Edgbaston team in contention, Clarke among his return of four for 42 when pulling to mid-on.
Bell's innings was the key factor in what began as a good day for Warwickshire. This was a classy performance from start to finish and fully befitting of a batsman who played in 161 one-day internationals.
After a delayed start, Warwickshire could easily have fallen off course. They lost Jonathan Trott, caught behind off Hastings in the third over, and then Sam Hain was caught and bowled by Ed Barnard after making 34.
Bell contented himself with four boundaries in a steady but hugely valuable half-century. It was Tim Ambrose who first upped the rate, punching 43 from 56 balls in a stand of 82 before popping up a simple catch from a half-checked shot.
This was a first wicket for Brett D'Oliveira and the young leg-spinner soon had a second when Aaron Thomason holed out to Barnard at long-off.
However, Warwickshire quickly turned this into a profit as Rikki Clarke set the ball rolling for a tidal wave which ultimately raised 112 from the last 10 overs and as many as 60 from the last four.
The powerful all-rounder clumped six sixes in an unbeaten 84 from 52 balls and in all put on 126 in 13.5 overs with Bell, who was finally out for 104 (129 balls, nine fours) when driving Hastings straight to Daryl Mitchell at cover.
The rain arrived on cue in the interval but fortunately it did not last as long as some had forecast. The reduction in overs prompted debate. Some thought it made Worcestershire's task easier, others felt seven-an-over was tough.
In the event they ran into difficulties. Moeen Ali edged Keith Barker's second delivery, Mitchell chipped Thornton to deep square leg, Tom Kohler-Cadmore was caught behind attempting to pull Thornton and Barker's return from long leg ran out D'Oliveira.