Derbyshire 283 (du Plooy 122, Dal 90, Rushworth 7-44) and 320 for 6 (du Plooy 134, Guest 116, Rushworth 4-44) lead Durham 296 (Mackintosh 51, Pettman 3-40, Thomson 3-48) by 316 runs
Du Plooy and Guest combined for a mammoth stand of 248 for the fifth wicket to take the contest away from the home side, recovering from the loss of two early wickets that had put the visitors in trouble at 36 for 4 in the first hour of the day.
The two Derbyshire batters were outstanding as Du Plooy scored his second century of the game, while Guest passed three figures for the third time of the campaign to leave their side in command at the close at 329 for 6 with a lead of 316 and the potential of an overnight declaration.
After reducing the visitors to 19 for 2 in the evening session on day two, Matt Salisbury ramped up the pressure on Derbyshire by pinning Luis Reece lbw for 12 after the opener opted to leave a straight delivery. Rushworth then claimed his 10th wicket of the game by ousting Wayne Madsen for nine, leaving the visitors in a precarious position with a lead of only 23.
The visitors were in dire need of a partnership to calm proceedings, and Guest and Du Plooy rose to the occasion in sublime manner. They ushered Derbyshire into the lunch break to stem the tide and force Durham captain Scott Borthwick to alter his plans.
After the break, Guest and Du Plooy reached their half-centuries in the same Liam Trevaskis over and continued to lay the foundations of a match-winning position. Guest had been stymied in the morning session, but moved through the gears against a toiling Durham attack in the afternoon under the baking sun at Chester-le-Street. The bowlers found no life in a flat pitch, and it allowed Guest and Du Plooy to capitalise to great effect, turning the momentum of the game in the favour of Derbyshire.
Du Plooy was unfettered and continued his fine form from the first innings, offering nothing to the home side in a controlled knock. For the second time of the partnership, both men reached their milestones in the same over as Du Plooy became the 19th Derbyshire player to score two hundreds in a match. Guest followed his team-mate to three figures from 216 balls, securing his third ton of the campaign along, pushing their partnership past 200, Derbyshire’s highest for the fifth wicket against Durham.
Du Plooy’s outstanding innings was finally ended by Rushworth with the new ball finding the outside edge, but only after the left-hander notched his highest score of the campaign. Guest soon followed for 116 lbw to Salisbury, but the visitors were already entrenched in a dominant position before Anuj Dal and Hilton Cartwright worked their lead past the 300-run mark at the close.