Derbyshire 275 and 237 for 5 (Chanderpaul 62*, Slater 60, Madsen 59) lead Essex 277 (Browne 132*, Palladino 4-65) by 235 runs
Nick Browne wrote his name in the Essex record books but Derbyshire hold the initiative after another absorbing day at Chesterfield.
Browne, 23, celebrated his maiden first-class century and became only the 10th Essex player to carry his bat when he was left unbeaten on 132 as his side were bowled out for 277. He occupied the crease for a minute short of seven hours but a burst of 4 for 14 in 45 balls from former Essex paceman Tony Palladino restricted the visitors to a slender lead of two.
Derbyshire skipper Wayne Madsen made his second 50 of the game and Ben Slater and Shivnarine Chanderpaul also made half-centuries as Derbyshire ended day three on 237 for 5, a lead of 235.
All the attention was on Browne at the start with the opener 14 short of a hundred but there were no nervous 90's as he cut Mark Footitt for four before turning Alex Hughes behind square for the two runs that took him to three figures.
It had been an impressive demonstration of concentration from the left-hander, who with former Derbyshire all-rounder Greg Smith had taken Essex to within 34 of Derbyshire's total when the new ball blew away the lower order.
Smith pulled Footitt for six but then nibbled at one from Palladino and Graham Napier never looked comfortable before he was lbw to Tom Taylor with only five runs added.
Palladino moved one away to take the edge of Tim Phillips's forward push and Browne was running out of partners when Tom Moore steered Palladino into the hands of second slip.
He survived a difficult swirling chance to midwicket before Reece Topley became Palladino's fourth victim which meant Browne had become the first Essex player to bat through an innings since John Stephenson made an unbeaten 113 at Taunton in 1992.
The clatter of wickets continued when Napier nipped one back to trap Paul Borrington lbw with only a run on the board in Derbyshire's second innings. But that was the visitors' last success until just before tea as Ben Slater and Madsen took control with a stand of 125 in 37 overs and they were largely untroubled until a run-out gave the game another twist.
Slater, for 60, slipped setting off for a second run leaving Madsen, on 59, stranded when the throw came in from deep point and the opener joined him in the pavilion shortly after the interval when he pulled a ball from Phillips into his pad and was caught by James Foster diving from behind the stumps.
Alex Hughes was lbw trying to sweep a straight ball from Phillips but Chanderpaul was soon placing the ball skilfully and reached his fourth Championship 50 of the season from 76 balls as the lead climbed past 200 leaving Derbyshire with the edge going into the final day.
Home bowler Palladino admitted he was pleased with the way his side began day three, and he said: "We knew we had to come hard this morning and really be disciplined and not let them get too much of a lead. We bowled pretty well and the wickets came for us so we were pretty pleased with the morning's work."
While, Browne was delighted his family could share in his celebrations, saying: "It means massive amounts, my parents and family were down yesterday and stayed on to watch me get it today and that was very nice.
"I walked off at tea and saw my mum and dad in tears and how proud they were so to see how much it meant to them was really good."
Derbyshire vs Essex
LV= County Championship Division Two
England Domestic Season