Worcestershire 170 for 0 (Mitchell 85*, Libby 80*) trail Warwickshire 355 for 9 declared (Rhodes 207, Hain 55, Morris 5-80) by 185 runs
Warwickshire captain Will Rhodes scored his maiden double century before Worcestershire openers Daryl Mitchell and Jake Libby launched a powerful response on day two of the Bob Willis Trophy encounter at Blackfinch New Road.
Rhodes extended his overnight 142 not out - already a career best - to 207 before he became one of five victims of Worcestershire paceman Charlie Morris. The 25-year-old helped Warwickshire secure three batting points as they reached 355 for 9 declared shortly after lunch.
It was an impressive and composed contribution from the former Yorkshire CCC all-rounder who replaced Jeetan Patel as Bears skipper during the winter.
Rhodes gave only one chance - on 123 off Mitchell yesterday evening - and received excellent support from England Under-19 player Dan Mousley, who reached, 47, during a fourth wicket stand of 128 in 40 overs.
Mitchell would have admired the powers of concentration shown by Rhodes, who batted for more than eight hours, as someone renowned himself for occupying the crease. He demonstrated for the umpteenth time the same sort of qualities in making a half century - his third of the campaign - as he and Libby posted a century partnership in 39 overs.
By the close Mitchell had moved onto an unbeaten 85 from 183 balls with 10 fours and Libby 80 not out from 167 deliveries with seven boundaries.
Home keeper Ben Cox collected five more catches to take his tally to 22 - the highest in the competition - as Warwickshire lost late wickets in an effort to force the pace in their 120 overs.
But on a sluggish, unresponsive pitch, offering little encouragement to the bowlers and described as "turgid" by Warwickshire batsman Sam Hain, it is hard to imagine anything but a draw particularly with an uncertain weather forecast on the horizon.
Rhodes, whose previous highest score of 137 was achieved against Gloucestershire at Edgbaston two years ago, reached his 200 with a pull for a single off Ed Barnard 15 minutes before lunch. It was completed from 321 balls and contained 21 fours.
Warwickshire, who resumed on 228 for 3, stepped up the tempo today in search of bonus points on a slow pitch.
Rhodes brought up the 250 with a pull to the ropes at Worcestershire captain Joe Leach's expense and then collected 4-2-4-2 off successive deliveries from the same bowler.
Mousley was playing only his second first-class match and showed the promise evident when impressing in the winter Under-19s ICC World Cup before
Worcestershire broke through with two wickets in successive overs.
Morris induced an edge from Mousley, who faced 134 balls and hit five fours, through to Cox who then held onto a nick from Michael Burgess in the next over from Ed Barnard.
But Worcestershire had to be content with one bowling point as Warwickshire ended on 319 for 5 from 110 overs.
New batsman Tim Bresnan made a breezy 17 before pulling Morris into the hands of Libby at deep square leg.
Rhodes eventually succumbed to Morris when he nicked through to Cox after going for a big hit down the ground. In total he faced 328 balls and struck 22 boundaries.
Morris completed his five-wicket haul when Craig Miles skied a catch to Brett D'Oliveira at mid-wicket shortly before the declaration.
When Worcestershire launched their reply, Mitchell and Libby, recruited last winter from Nottinghamshire, continued their recent good form and posted a century stand in 39 overs.
Neither batsman was particularly troubled with Mitchell first to a half century off 103 balls with a steer to third man off Oliver Hannon-Dalby for his seventh boundary.
Libby followed him to fifty with a single off Ryan Sidebottom - from 122 balls with four fours.