Windsor's Paul Coyne was dismissed for a tackle on Luke Evans before Royalists skipper Mark Cooper put through his own net just before the break.
Matthew Platt made it 2-0 from the edge of the box before Windsor started a fightback with a goal from Ryan Parsons. Dean Harper's penalty looked to have put the game safe, but an injury-time effort from Michael Chennels ensured a nervy last few minutes.
Windsor and Eton have had an extraordinary season under Keith Scott’s leadership and could take the title at the end of the season. So it was with much trepidation that Derek Sweetman prepared for this important local clash, not least because the reverse fixture had seen the Royals batter a seriously depleted Rebels side 6-2, and that the Royalists came into the game on an unbeaten run of 18 league games.
For the home squad, the return of Luke Evans and Dean Harper in the back four clearly galvanised the troops. Slough sprung out of the blocks and early attempts were denied by a hardworking Windsor defence, with Danny Jordan having a shot blocked and Dean Harper heading over after Platt had crossed from the left.
The confident and competent start of their local rivals had left Windsor on the back foot, and Slough looked the stronger side for the majority of the first half. Windsor still looked dangerous in spells, with Wallace stretching but just failing to make contact to a far post cross. Both sides exchanged long shots at goal, with Williams firing over twice for Windsor and Byron Bubb curling a free kick over the bar.
The first signs that the game would take a bad-tempered turn occurred when Dean Harper and former Rebel Adam Wallace were both cautioned for dissent after Martin Williams had cynically taken out Makh by the touchline. Williams was booked but in the eyes of many, was lucky to stay on the pitch for the second half after a series of fouls in the first half.
The major talking point arrived eight minutes before the break as Paul Coyne was dismissed. Coyne, a hero for Windsor after his 40-yard strike against Slough back in October, turned villain as his lunge on Luke Evans was punished with a straight red card from referee McGann.
The continued pressure and effective passing through the midfield eventually paid off at the end of the half as a strong flat cross from Yashwa Romeo was turned into his own net by Windsor’s captain Mark Cooper. The goal may have been fortuitous, but the result was probably fair - Slough had looked stronger, more accurate, stronger in defence and more dangerous in open attacking play.
Slough had a good chance to double their lead just before half time as Platt was played in by Bubb, but the striker’s first time effort was too weak and easily gathered by Bullivant.
With Windsor reorganising at half-time with the introduction of Wilson and Weedon, the Royalists pushed forward and went close as Steve Butler’s header was cleared away from the goal with Matt Seedel lurking.
Jamie Jackson produced a fine save to keep Slough ahead from another Butler header, diving full stretch to turn the ball away.
Slough continued to press, looking to make their man advantage count, and were rewarded, again in slightly fortuitous circumstances. Matthew Platt’s medium paced strike from the edge of the box caught Windsor keeper Bullivant off guard as the ball bobbled over his outstretched arms and into the back of the net to give the Rebels a cushion.
The yellow cards continued to flow for both sides for a series of niggly fouls, and the Rebels looked to shore up the midfield with the substitution of Jordan for Fermie - but Windsor were still in the game, and came back into contention with just five minutes remaining courtesy of a goal from the hardworking Ryan Parsons - and suddenly the game was in the balance.
To the home side’s credit, the Rebels didn’t panic, and continued to make full use of the space as Windsor piled forward. Slough strung together some beautiful passes, and a flowing move involving the excellent Makh resulted in Byron Bubb getting in behind Windsor’s back line. Bubb’s shot was blocked, but the ball rebounded kindly back off a Windsor player. The Grenadian, clearly onside as a result, looked to jink past Matt Seedel, but was hacked down and the referee had no choice but to award a penalty.
Dean Harper, returning to the side for the first time in over a month, duly converted the penalty with a strong, rising middle-of-the-net strike to spark what could have been premature celebrations.
In true Slough style, the last few minutes were excruciating. A long free-kick was delivered by Bullivant into a crowded Slough penalty area and Windsor top-scorer Chennels followed up after a shot had hit the post to make it 3-2 in injury time, and suddenly the hosts found themselves clinging on for the win.
Cling on they did - but not before Steve Butler fired a last-gasp effort straight at Jamie Jackson - and the elation was clear for all to see, as Slough gained some revenge for the heavy defeat earlier in the season.
Windsor & Eton Line up
Bullivant, Tilbury, Ryan Parsons, Cooper (c), Butler, Seedel, Coyne, Williams, Wallace (Wilson), Chennels, Jake Parsons (Weedon). Subs not used: Cahill, Porter.