Wanderers recovered from 3-1 down to win 4-3 in another monumentous occasion at Adams Park, with Scott Kashket netting the winner in stoppage time.
The hosts twice trailed by two goals to Southend, who went 2-0 up through Brandon Goodship and Stephen Humphrys, before Mark Milligan netted an own goal before the break to give Wycombe hope.
Humphrys looked to extinguish that hope with a second excellent after early in the second half, but Kashket, Anthony Stewart and Kashket again tipped the game on its head in incredible fashion.
Gareth Ainsworth made four changes from the side that started in Tuesday’s 1-1 draw with Fleetwood, as Jack Grimmer, Matt Bloomfield, Alex Samuel and Scott Kashket came into the side as Wanderers looked to attack a Southend outfit yet to claim a point in League 1.
Wycombe began brightly, with Fred Onyedinma causing problems with his pace down the left, and Samuel’s bustling hold-up play enabled the home side to keep the ball high up the pitch. Joe Jacobson drilled wide from 25 yards with the game’s first chance, but then out of the blue the visitors took the lead, when Stephen Humphrys burst towards the box and although Kashket got a toe the ball when making a tackle, it fell kindly for Brandon Goodship to find the net with a one-touch finish.
The goal rocked the hosts and opportunities dried up for a 10-minute spell, though Darius Charles did well to create a half-chance for himself when winning the second ball from Jacobson’s deep free-kick, though he volleyed wide into the side netting.
But on the half-hour mark, disaster struck again, and after Humphrys had done so well to carve out the first goal, he wrote his own name onto the scoresheet with a stunning effort from 25 yards, finding enough space outside the area to bend an unstoppable effort past Ryan Allsop.
Adams Park was stunned, but a lifeline arrived six minutes later after excellent play from Scott Kashket, whose jinking run towards the box was thwarted by John White but the ball cannoned comedically off Shrimpers captain Mark Milligan and into the bottom corner.
Harry Lennon was booked for a nasty challenge as United battled to hold on to their lead before the interval, before Onyedinma was forced off with an injury as David Wheeler – the hero of Adams Park seven days earlier – took his place.
However, despite a series of successive corners before the interval, it remained 2-1 at half-time, and the last thing Wanderers needed was a slow start to the second period – which is just what happened. Humphrys scored a third – his second – with an instinctive effort from outside the box when he found a yard of space to lash one towards the bottom corner.
Time for the Beast, then, but before Adebayo Akinfenwa had time to step foot on the pitch, his strike partner Kashket had halved the deficit, staying onside to meet Wheeler’s blocked shot and tuck the ball past Nathan Bishop from close range.
Akinfenwa replaced Alex Pattison before Kashket almost levelled matters two minutes later, smashing narrowly over the bar when Jack Grimmer picked him out on the edge of the box, and Southend made their first change when Layton Ndukwu replaced Goodship.
Wanderers began to crank up the pressure with Southend sitting deep, and were unlucky not to level, firstly when David Wheeler hit the bar with a header from Jack Grimmer’s cross, and then when Dominic Gape crashed a shot against the post moments later.
Southend brought off Humphrys for Theo Robinson with 20 minutes left on the clock, before Bishop was booked for time-wasting having been warned as early as the first half.
Kashket saw a chance tipped past the post on 82 minutes, but gradually Southend were finding a better way of stifling the hosts, with Nick Freeman introduced for Alex Samuel in a bid to change things up.
Wheeler was set free down the right-hand side of the box but well thwarted by Bishop, with the ball then being whisked off Akinfenwa’s head from the ensuing cross.
Southend brought on Andre Blackman for Elvis Bwomono as the clock ticked towards 90, but the defensive change couldn’t prevent the equaliser on 89 minutes, when Anthony Stewart blasted home after excellent hold-up play from Akinfenwa. Nick Freeman did excellently down the left to deliver an excellent cross, and when the ball fell to Stewart, he made no mistake with a crisp finish.
Cue six minutes of stoppage time, and in typical Wycombe fashion, they completed the turnaround. Freeman again was the catalyst, dinking the ball through for Kashket, who cut inside his man and finished with aplomb. Limbs ensued.
But they weren’t done. Matt Bloomfield successfully contested a 50/50 to prod the ball on to Freeman, who fed Kashket for the sumptuous winner as the little genius cut inside his man and curled home to spark pandemonium for the second weekend in succession around Adams Park.