Mitchell's previous Championship best was 134no against Glamorgan in 2006
Daryl Mitchell hit a magnificent first double century as Worcestershire made nonsense of this season's County Championship struggles at Taunton.
Fresh from confirmation of relegation last week, coach Steve Rhodes rung the changes, bringing in fresh blood.
And his youngsters responded, Mitchell reaching his 1,000 runs in an unbeaten 232 against Somerset out of 408-4.
He was backed by David Wheeldon, who also hit a career-best 87, the fifth-wicket pair making an unbroken 217.
Having been 234-4 at tea, the majority of that came in the final session as the pair plundered 174 in 32 overs as even hapless Worcestershire proved they could bat on this Taunton run paradise.
Mitchell reached the benchmark of 1,000 runs in a season for the first time just before the close.
But he had one big escape, being dropped by wicketkeeper Craig Kieswetter on 28.
The home side, still trying to nail down runners-up spot in the County Championship (and a cheque for £225,000)had elected to field an all-seam attack, all-rounder Arul Suppiah being their only spin option, and were made to suffer in the sunshine.
David Stiff made the first breakthrough on 73 when Stephen Moore edged an attempted pull shot.
But, after helping Mitchell take the total to 109, visiting skipper Vikram Solanki was visibly annoyed with himself when departing to an expansive drive, to be caught at slip in the final over before lunch.
Somerset looked to be getting on top when Kieswetter took a good diving catch off Charl Willoughby to dismiss Moeen Ali for just a single.
But Mitchell, growing in confidence, then dominated a fourth-wicket stand of 80 with Alexei Kervezee, who made 19 before top-edging a cut shot off Stiff to Suppiah at point.
And, in the final session, helped by a short boundary on the town side of the ground, Somerset's bowlers were put to the sword.
On only his fourth first-class appearance, Wheeldon reached his maiden Championship half-century, as he and Mitchell became increasingly aggressive.
But it was Mitchell's day and, having long since passed his previous best first-class score (140 not out against Oxford University earlier this summer), he raised both arms having cover-driven Willoughby for the boundary that brought up his double century.
And, when he resumes on Thursday morning, with Worcestershire already relegated and team responsibilities allowed to be put to the back of his mind, Mitchell may have two chief individual targets in mind.
Murray Goodwin's 344 for Sussex last month on this much-discussed Taunton track remains this season's highest first-class score.
And an even bigger mountain to aim at is the famous 405 hit by Mitchell's former Worcestershire colleague Graeme Hick at Taunton back in May 1988.
Earlier in the day, the main headlines had belonged to 17-year-old schoolboy Ben Cox, who was summoned for his County Championship debut following an ankle injury to the county's first-choice wicketkeeper Steven Davies.
Cox, still a pupil at Bromsgrove School, has played four Second XI games this summer, as well as turning out for the county's Under-17s.
Staffordshire-born Wheeldon's success came at the expense of out-of-form Ben Smith, the county's fielding coach, who was dropped after hitting just 565 runs this summer in 13 County Championship matches.
Double centurion Daryl Mitchell told BBC Hereford and Worcester:
"I rode my luck a bit at times early on. But, when I got in, I played pretty well and managed to make hay while the sun shone.
"Sometimes you have luck and you have got to make the most of it.
"I have had a couple of rough decisions here and there this year so you take the rough with the smooth."
Bookmark with:
What are these?