A goal midway through the second period by Idir Ouali was the difference in the end against a Reading team which included many youngsters; Bryan Verboom was dismissed for Kortrijk in the closing stages for a reckless challenge.
After a bit of early pressure from the Belgians, it was the Kortrijk stopper who was first called into action; Danny Loader’s driving run resulted in free-kick, who Josh Barrett curled on target – only to be denied by goalie Thomas Kaminski.
Then Barrett’s raking ball for Loader almost resulted in a goal, but the teenager was denied with a firm block. And when Sam Smith’s first-time effort squirmed free from a block, Stephen Quinn’s powerful effort rose just over the bar.
Strong running from Andy Rinomhota nearly created a breakthrough – after riding a few cynical challenges, he was finally chopped down decisively on the edge of the area as he shaped to shoot. And then from the resulting free-kick, Jordan Obita’s strike clipped a head in the ball and flew over.
Kortrijk had a couple of chances before the break, but Stijn De Smet and Idir Ouali both pulled their efforts past the post, shortly after Lucas Rougeaux had headed a free-kick into George Legg's grateful arms.
It was the Belgians who had the first opportunity of note in the second period - a whipped delivery from the right-hand side was met with a powerful header, which flashed fractionally over the bar of half-time sub goalie Lewis Ward.
However the deadlock was broken in similar circumstances, as a deep delivery was met with a stretching header by Ouali, which just squeezed inside the near post.
The Royals looked to reply straight away; Obita's deep free-kick, curling inwards, found its way to Jake Cooper on the far side but he couldn't make a true connection as he stretched to meet it.
Smith, working hard as the most advanced player, showed willing running with the ball on the right and entered the area - he was taken down, but not enough to convince the ref to award a spot-kick.
He was close to getting on the end of Tyler Frost's low delivery, but arrived just after the goalkeeper and caught the Kortrijk man.
Soon after, in what appeared to be an attempt at retribution, Smith was caught by a flying kick by Verboom - poorly disguised as an attempt to play the ball - resulting in a red card.
Full-time: Reading 0-1 KV Kortrijk
Reading: Legg (Ward HT), Frost, Obita (Richards 67), McShane (c), Cooper, East, Quinn, Rinomhota, Barrett, Loader, Smith.