Matt Critchley’s second century of the season put Essex in the driving seat for a fourth successive LV+ Insurance County Championship victory on a strange day of substitutes and concussion repercussions at Chelmsford.

  The 26-year-old faced just 168 balls in rattling up 117 runs as Essex put Kent to the sword while building a first-innings lead of 251. Critchley entered at 158-3 and departed 64 overs later on 408-7 when he picked out long-leg to give part-time spinner Jack Leaning a rare wicket.

  In between Critchley shared a century stand with Simon Harmer – who hit a swashbuckling season’s best 83 not out from 92 balls – and other partnerships worth 71 and 49 with Paul Walter and Adam Rossington respectively. In the process the former Derbyshire all-rounder took his season’s tally in the Championship past 700 runs.

  Sir Alastair Cook had laid the foundations with a 176-ball 87, but some lusty late six-hitting by Critchley, Harmer and Doug Bracewell gilded the lily as Essex declared on 458-8. Hamid Qadri bore the brunt with figures of three for 120, while the Indian international Arshdeep Singh returned best Championship analysis of three for 58.

  And to cap Essex’s day, Twanda Muyeye departed to the last ball of the five overs left for Kent to see out when he went lbw pushing forward to Sam Cook for nought. Kent finished on 4-1.

But the real drama of the day came before play with the news that Nick Browne had retired hurt after feeling groggy overnight and failing an off-field concussion test. The left-handed opener was hit on the head by a short ball from Arshdeep Singh in the evening session but batted on for a further two and a half overs before being visibly ill after the penultimate delivery of the day. He then passed an on-field check and saw out the over.

Robin Das, who had originally stood in as the nominated substitute while Dan Lawrence made his way back from Old Trafford where he was stood down by England, then became Browne’s replacement.

  Das lasted five balls before he became another entry in the scorebook that needed an asterisk: the concussion substitute was caught by the substitute wicketkeeper Harry Finch, standing in for Jordan Cox who further depleted Kent’s resources with a thigh injury.

  Having put on 117 for the first wicket, thanks to the efforts of three men – but mainly Cook – Essex lost another almost immediately when Tom Westley was trapped lbw to give Arshdeep a second wicket.

  Cook had looked in sparkling form the night before, stroking a dozen boundaries in his 64. But he batted for a further hour-and-a-half in the morning session, adding just 23 runs from 70 balls before looking a little disconsolate at being judged lbw to former Essex seamer Matt Quinn.

  Lawrence, having made the journey down from Manchester, played an entertaining cameo of 25 that included an effortless six over midwicket before he attempted to sweep Hamid Qadri in a similar direction only to become a third lbw victim.

  Critchley hammered Qadri over long-leg for the six that took Essex beyond Kent’s first-innings 207 with only four wickets down, though it had taken them 17 overs longer. However, Walter’s 90-ball 45 was ended by the third delivery with the new-ball as he played down the wrong line to Arshdeep.

  Rossington twice straight-drove Joey Evison for fours in a bright partnership with Critchley before he was deceived by Qadri’s flight and turned to see his stumps disturbed.

  Once Harmer had got off the mark to his 28th ball, he cut loose and needed just another 51 balls for his half-century, reached with a huge six off Qadri. But it was Critchley who caught the eye with some breathtaking, but orthodox hitting, and reach three-figures from 161 balls by pulling Quinn through midwicket for his 14th boundary that included two maximums.

  Harmer, with five maximum, traded maximums with Doug Bracewell off the beleaguered Kent spinners before the New Zealander was stumped to prompt the declaration.

Essex’s Matt Critchley said: “It was a pleasing century because it was quite a slow wicket and I had to work hard early on to get set. A lot of runs came later as the bowlers got tired particularly in the last session. As I said, it’s quite a slow wicket and they set defensive fields as you would on those type of wickets so there weren’t too many gaps there.

  “I had to be patient and wait for the bad balls to come along although there weren’t too many of them until later but towards the end, I really got going and we set ourselves up really well in the game.

  “I’ve worked hard on my game with the bat and look to capitalise on the bowlers missing their length and obviously it’s so short here that when you beat the field, you get four.

  “It was good batting with Simon Harmer, we put on over 100  and he batted beautifully.  It was also nice to bat with Paul Walter and Rosso (Adam Rossington) and put on some decent partnership with them and get a decent score on the board.

  “Unfortunately, Simon ran out of time to get his 100 because we wanted to get five overs at Kent this evening.

  “Probably Sam Cook and Simon Harmer are two bowlers you just would not want to face when you’ve got to go out for five overs. With the ball spinning for Harmy and nipping back for Sam. Thankfully we got a reward with the last ball of the day.

  “Against our bowling attack, I feel it will be difficult for Kent, it’s hard enough to score against them on this wicket and they are going to have to take risks if they want to score or sit in for a long time if they want to survive. That’s the beauty for us of being 250 in front on first innings.”

Kent bowling coach Simon Cook said: “It’s probably not been our best day when you look at the scoreboard, but having said that the first two sessions we held them really, really well. We had plenty of opportunities, we had three or four clear chances which unfortunately we couldn’t take. We actually bowled two really good sessions up to tea.

  “We knew they were going to start to come hard and unfortunately we couldn’t really hold on to those chances and they came to bite us in that last session when they put us under a bit of pressure. As a result we end up batting this evening rather than batting an hour into tomorrow.

  “It’s one of those pitches that once you get in you can start to score. It’s a tough pitch to start with. Spin is obviously going to play a big part tomorrow, but once you get in it does allow you to free your arms. It’s a fast-scoring ground as we’ve seen in the T20s. it’s a frustrating day having controlled two sessions really well, created plenty of opportunities and we didn’t capitalise on that in the last session.

  “Tomorrow is going to be trying to take as much time out of the game as possible by batting sensibly. I still think we’ve got to put pressure on, certainly the likes of Simon Harmer, who I think Grant Stewart showed in the first innings didn’t let him settle. It’s a different proposition when we’re putting pressure back on.

  “It’s not just a case of trying to sit in and bat for a day, it’s still a case of tyring scoring runs with good intent and pass 250 runs and you never know what might happen. Whether the rain comes or not on Saturday, we obviously can’t count on the rain, but you never know going into day four if you can post something and the pitch deteriorates to that level we suddenly come into the game. But it’s certainly a big day tomorrow.

  “Our injured men [Denly and Cox] will bat tomorrow, probably down the order as the rules dictate. Finchy will come in up the order. Then we’ll see when they’re available and they can come in. I seem to remember last year we had injuries at this time.

  “But today we had [the long-term injured] Hogan, Gilchrist and DBD here and two of them ended up on the pitch [as substitutes] because of injuries. It’s starting to get to that part of the season where you’ve played a lot of cricket and these things happen. We’ve got an uphill battle here on in and we’ve got to focus on that rather than how stiff and sore we are.”