For the first of three opening games against Ryman Premier newcomers the Dons took on newly relegated local rivals Carshalton Athletic at Colston Avenue.
Paul Barnes failed a late fitness test, leaving Richard Butler to start up front with Rosco D'Sane as the joint spearhead of Dave Anderson's preferred 3-5-2 formation.
The visitors started brightly, forcing a shot in the first minute and following up a couple of minutes later with a right-sided free kick from Haswell that whipped past the post.
Athletic then spent the next ten minutes pushing forward and the Dons only stayed level thanks to a brave Andy Little save at the feet of Craig Dundas. Although this was the only clear chance during that spell, it was against the run of play when AFC Wimbledon took the lead with sixteen minutes gone. Little's big goal kick was misjuged by the Alhajie Jabbie and Richard Butler took full advantage, taking one touch before firing just inside Paul Seuke's right-hand post.
The goal had the dual effect of knocking some of the wind out of Carshalton and increasing the Dons' confidence, allowing them to play the ball around more freely. This gave the Dons the advantage in what remained of a tight first half, although Carshalton had more of the ball.
Wes Daly went close after 24 minutes, nipping in to knock the ball loose in midfield before latching onto Antony Howard's clever back-heeled pass and running a full forty yards before unleashing a shot that sailed just wide. Athletic almost took advantage a couple of minutes later when Andy Little dropped the ball after clattering into a defender on the way down from catching a corner, but Mark Rooney threw himself in front of the resultant goalbound effort.
The ref finally punished a series of crunching Carshalton fouls after half an hour with the first yellow card of the afternoon, Alhajie Jabbie guilty of a wild challenge on Daly, but evened the count a few minutes later when Rooney knocked over ex-Don Steve Gibson on the right wing.
As the first half came to a close, Little was again called into action, tipping over Mark Marshall's swinging left-sided free-kick from just under the bar and then holding the ball well under pressure from the following corner.
Steve Wales then swept the ball forty yards across-field for Haswell to run on to, and a clever one-two with Richard Butler gave the winger a sniff at goal, but he shot high and wide.
HALF TIME: Carshalton Athletic 0-1 AFC Wimbledon
The men in blue took an early initiative in the second half and Byron Bubb's free-kick was scrambled over the bar by a defender.
Six minutes in and Bubb's long corner found Lee Kersey at the back post, he headed it back across goal and Steve Butler got to it first but could only glance it wide. Soon after Rosco D'Sane cleverly held up a long ball from the back before beating his man and pushing the ball across for Daly to shoot wide.
Daly was not to be stopped though, and in the 58th minute he collected the ball twenty yards out and juggled and weaved his way past what appeared to be the entire home defence before a foot from behind took him down as he prepared to shoot. D'Sane stepped up to confidently pass the resultant penalty into the net.
Five minutes later Richard Butler and Haswell again combined well down the left and the latter laid the ball into Bubb's path, resulting in a curled shot that didn't trouble the 'keeper. By this time Daly had retired after taking an unintentional whack to the head. With a quarter of an hour left Richard Butler also left the fray and ex-Youth teamer Steve Goddard replaced him for his competitive debut. It could have been a dream debut a minute later when D'Sane found himself crowded out on the edge of the box, but found Wales on the right. His looped cross fell kindly for the youngster, but he mis-cued and the ball was cleared.
With just under ten minutes remaining poor defending allowed Craig Dundas to turn his man on the edge of the box and half the arrears by stroking the ball inside Little's right hand post. The remainder of the game was all Carshalton and only some desperate defending kept the home side from getting an equaliser. Deep into injury time a goalmouth scramble was somehow cleared and the ref blew to record the Dons' fifth consecutive opening day victory.