Terry Brown insisted his side's first-half performance offered some positives and the Dons boss can at least take consolation from having got the hardest one out of the way.
The hosts were just 2-0 down at the break with an experimental defence including Aaron Downes and Steven Old having emerged with credit, but the second-half was completely different as Premier League new boys Reading showed just why they will be mixing it with the elite next season.
Brian McDermott's men cracked four goals in the opening eight minutes of the second-half and it was then a case of damage limitation for the hosts. As pre-season friendlies go, it was a tough lesson for the Dons, but it should get a little easier in the coming weeks with Wimbledon building up their fitness against more moderate opposition.
The Royals brought a strong squad with them that included new signings Garath McCleary and Danny Guthrie in his starting line-up. Wimbledon's starting back four was completed by full-backs Curtis Osano and Jim Fenlon, who were both making their first-team debuts. Sammy Moore was given the captainís armband and there was also a start in midfield for another Wimbledon academy graduate in the form of Frankie Merrifield.
The rest of the starting 11 had a more familiar feel about it with Seb Brown in goal and Brendan Kiernan playing in the role behind the front two of Jack Midson and Christian Jolley.
Reading started as they meant to go on, but the Dons were holding their own until the 26th minute when newcomer Aaron Downes gave away a penalty. The ex-Chesterfield defender could consider himself a little unlucky as he was deemed to have tripped Noel Hunt, but there was no doubting the subsequent penalty with Adam La Fondre driving home emphatically. The same player doubled his and the Berkshire side's tally on 44 minutes as he finished clinically after good work from Kaspars Gorkss.
Only Old and Osano remained for the Dons at the start of the second half with goalkeeper Ben McNamara among the changes. Dons fans were offered their first glimpses of new signings Warren Cummings, Louis Harris and Stacy Long and striker Charlie Strutton was offered a chance to prove his worth.
It all started to go wrong for the hosts after the break when Jordan Obita crossed for former Tooting winger Michail Antonio to head home for a third. A couple of minutes later, Simon Church headed his first at close range and was then on hand to follow-up after McNamara had initially saved from Jason Roberts. It got worse when Obita made it six and just when it seemed McNamara was regaining some composure, Church sealed his hat-trick. The closest that the Dons came to a consolation was when Luke Moore volleyed wide of a post and Wimbledon will be hoping to quickly put this one behind them at Maidenhead on Tuesday night.
Such humblings are always hard to take even when itís a pre-season friendly, but all that really matters for Terry Brown is that his new-look side starts to gel before the first competitive match on August 14 at Stevenage in the Capital One Cup.