Luis Reece took 3-49 and remains unbeaten on 43 as Derbyshire dominated Day Two of the three-day fixture against Leeds/Bradford MCCU at The Pattonair County Ground.
James Taylor took 3-48 in his second first-class match, while Sam Conners also took his maiden first-class wicket as Derbyshire bowled the visitors out for 200.
After Derbyshire declared in the morning on 398-5, Ravi Rampaul opened the bowling for the hosts and got the breakthrough with the second ball of the day.
Josh Haynes was victim to a delivery that nipped back to take his off stump as Rampaul opened the session with a wicket maiden.
Oliver Batchelor and Taylor Cornall steadied the ship for the visitors as the pair came within a run of their half-century partnership before Rampaul returned to take his second of the morning.
Cornall (19) top-edged a well-directed bouncer from the fast bowler to Tom Lace at mid-wicket as Derbyshire looked to seize the upper hand.
Reece then got in on the act to remove Batchelor (21) as he edged a full delivery to Wayne Madsen at first slip to reduce the score to 53-3.
Debutant Conners then came into the attack to claim his first wicket for Derbyshire, removing Angus Dahl (14) as Madsen took his second catch of the innings.
Wickets continued to fall at regular intervals as Taylor returned to take his first wicket, trapping Darren Ironside for 10 to leave the score at 101-5 at lunch.
Taylor was bowling a probing line and he was rewarded with two wickets in quick succession after lunch.
He dismissed Saad Ashraf for 13, before Andrew Neal (9) was caught behind to reduce the score to 128-7.
Reece then also took two wickets in successive overs as Derbyshire closed in on a first-innings lead.
There was a late resistance from the Leeds/Bradford MCCU tail, as Stephen Cantwell (43) and Joshua Fallows (12 not out) put together a 64-run partnership.
Critchley then came into the attack to end the partnership, as Derbyshire bowled the visitors out for 200 with a 198-run first-innings lead.
Openers Reece and Billy Godleman got the hosts’ second innings off to a good start, as they passed their half-century partnership off 91 balls.
Godleman (39) was accelerating the score for the hosts to take the score to 76-0, before he was caught by Dahl attempting a big shot off the bowling of Haynes.
Reece continued his fine form as he finished the day unbeaten on 43, alongside Alex Hughes (9 not out) with the score 95-1, a lead of 293 runs.
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