The MK Dons side, managed by Spaniard Edu Rubio included a mix of first-team players and apprentices, with Aidan Nesbitt, Conor McGrandles and Thomas-Asante among the senior professionals named in the starting eleven – all with significant League One experience. Thomas-Asante also scored a hat-trick in the Quarter-Final win at Windsor.
For the Rebels, squad rotation was again key having played on Saturday and Monday, and with a trip to Dorchester to come this Saturday, Slough made six changes, including three of the back four. Simon Dunn made a welcome return to the bench but did not feature.
Slough made a bright start and were full of attacking intent. Chris Flood had a chance in the opening minute as he connected with an early James Dobson cross, but goalkeeper Alfie Jones turned the header behind.
Dobson smashed a half-volley well over minutes later and Slough continued to carry the greater threat with Perry Coles also firing off target with an ambitious effort.
However on 16 minutes Slough were undone by a long pass out from the back. MK Dons had tried on a number of occasions to release the pacy Thomas-Asante, and on this occasion he outstripped Mark Nisbet and Matt Day for pace and fired confidently beyond Jack Turner.
In response, Dobson tried a dipping volley which was initially awkward for Jones but gathered well at the second attempt.
But then, the visitors scored three times in seven minutes to effectively end the game as a contest.
Slough were the architects of their own downfall with the second on 28 minutes as Nisbet lost possession and left Thomas-Asante one-on-one with Turner – and he made no mistake, rounding the keeper before slotting home.
Two minutes later his hat-trick was complete as he slid in to convert a low cross from Giorgio Rasulo following a slick move.
And on 34 minutes Rasulo got in on the act. It looked all too easy for MK Dons, but Rasulo made it look so as he danced through the Slough defence before playing a one-two in the box and finishing with the outside of his right boot.
Coles worked hard to create a shooting chance for Dobson, but the winger fired over – and MK Dons should really have gone in to the half time break five goals ahead after another defensive mishap, but McGrandles curled the ball wide of the post.
Slough kept looking for a way back in to the game, and before half time threatened twice more, with a dangerous Dobson corner flying all the way across goal and Harrison Gilkes putting the ball wide at the far post from a low Dobson cross.
Turner made the first save of the second half from Thomas-Asante but Slough were next on the scoresheet. Perry Coles continued his goalscoring form, making it seven goals in six games as he worked hard to hold off Oran Jackson before firing past Jones.
MK Dons could have restored their four goal advantage almost immediately but Connor Furlong fired over with substitute Jay Bird, who had replaced Thomas-Asante, well-placed in the middle.
Turner was by far the busier of the two goalkeepers and he kept the score down with further saves from Matthew Sorinola and McGrandles, whilst Rasulo tried his luck from distance but put the ball over.
Bird was also denied by Turner later on after MK Dons had broken away with frightening pace, whilst Furlong was similarly frustrated.
A late rally from a clearly tired Slough saw Jackson put in a superb last-ditch challenge to block substitute Warren Harris, and in stoppage time the keeper dived bravely at the feet of Harris to deny him a goal after Dobson’s initial effort had rebounded back off the far post.
Slough will now prepare for three important league matches as they try to finish as high up the table as possible, and will hope for good news on Chris Flood after he left the pitch with an injury midway through the second half.
MK Dons Line up
Alfie Jones, Joe Evans, Matthew Sorinola, Connor McGrandles (Recoe Martin 82), Finn Tapp, Oran Jackson (c), Connor Furlong, David Kasumu, Brandon Thomas-Asante (Jay Bird 62), Giorgio Rasulo, Aiden Nesbitt (Liam Sole 74). Unused substitute: Deisin Ackom.