Essex 236 (Wheater 83*, Andersson 4-38) and 53 for 1 beat Middlesex 138 (S Cook 4-27) and 150 (Beard 4-21) by nine wickets
Unbeaten Essex all but confirmed their place in the Bob Willis Trophy final as South Group victors with an emphatic nine-wicket win over Middlesex.
Essex's place at Lord's seemed to have been confirmed when Derbyshire failed to get a batting point in their North Group fixture against Lancashire, which was met by cheers from the Essex dressing room. It meant Derbyshire could only match Essex's 90 points if they manage to win at Aigburth, but Essex's superior win record would still take them through.
However, due to the Covid-related abandonment of Northamptonshire's match with Gloucestershire, the ECB may yet decide to use net run-rate rather than matches won to determine the finalists. Essex are currently top in that respect too, although a freakish set of final-day results, including a rapid Derbyshire run-chase at Aigburth could yet derail them*.
Nevertheless, Essex will almost certainly face the winner of the Central Group - either Somerset or Worcestershire - for a five-day match starting on September 23 at Lord's.
Middlesex resumed with a slim lead of 25 runs, six wickets down, with the hope of the tail setting Essex a tricky fourth-innings chase. It didn't pan out how they would have dreamed overnight; instead, Sam Cook's fantasies were realised.
The fast bowler, who had taken four wickets in the first innings, beat James Harris' edge of the bat to uproot his off stump with his second ball of the morning, and he only needed another 13 balls to strangle Blake Cullen down the leg side, as the 18-year-old tickled through to wicketkeeper Adam Wheater - his first second-innings catch having pouched five earlier in the match.
He thought Thilan Walallawita had top-edged a bouncer behind three balls later, but the umpire correctly adjudged the ball to have deflected off the batsman's shoulder.
Cook was replaced at the Hayes Close End by Beard, on the back of three wickets in 21 balls on day three, who also struck immediately. Walallawita saw his leg stump cartwheeling towards the River Can as Beard unleashed a yorker - the 22-year-old ended with career-best figures of 4 for 21.
And in the next over, Tim Murtagh swung wildly and was stumped to hand leading wicket-taker Harmer his 34th scalp of the Bob Willis Trophy. Middlesex lost their last four wickets in just under 15 overs, as John Simpson was left unbeaten on 26 off 123 balls.
That left Essex needing 53 to seal an 11th straight first-class victory at Chelmsford. Alastair Cook and Walter marched to 41 as both struck four boundaries apiece in what appeared to a procession to victory.
Murtagh castled Cook to slow Essex, but Walter (20) clipped the winning runs off Nick Gubbins, who bowled his legspin while wearing a cap.
"It has been a shorter season and given the format we knew we needed three or four wins to get to the final, so to win four out of five and the other was rained off? You can't ask for much more," said Anthony McGrath, Essex's head coach.
"We have carried on from last season; it has been unbelievable consistency from everyone, and now we can look forward to a Lord's final. I was critical after the second day against Kent [the first game of the season] but since then we have been very good.
"In hindsight, today looks good but at the time you never know in cricket. The guys were straight on it this morning with the early wickets. Porter and Harms tend to get the plaudits, so Sam Cook and Beard go under the radar a lot. The way Cook has bowled this year he could easily have another 15 wickets, while Beard's spell really cracked the game open for us - he is improving all the time.
"We are mathematically in the final so the guys can relax and get a bit of lunch now. To play a five-day final at Lord's is special - you don't tend to get that in red-ball cricket, and it might not happen again."
*Permutations correct to close on Day 3