Stefan Kiessling's header for Bayer Leverkusen missed the target and the striker even held his head in frustration, but somehow the ball crept through the side-netting and Brych signalled a goal.
Leverkusen accepted the gift, that put them two goals ahead and on the way to a 2-1 victory, but it was certain to spark post-match controversy.
Sidney Sam had given Leverkusen a first-half lead, and Kiessling's bizarre goal meant Sven Schipplock's late reply was worthless to the hosts.
Sam struck in the 26th minute with a low shot from outside the penalty area beyond Koen Casteels.
The second goal is guaranteed a place in football history for being a refereeing blunder, and it remained to be seen whether Hoffenheim would file a complaint.
Kiessling rose to meet a corner delivered from the left by Gonzalo Castros and headed the ball into the side-netting. Implausibly, the ball managed to burst through a small hole in the net and rippled the inside of the goal.
Since the ball emerged as if it had crossed the line, the referee awarded the goal and Kiessling's initial dismay at his miss turned to a mixture of joy and embarrassment.
Several Hoffenheim substitutes raced behind the goal to examine the netting for themselves, calling the attention of the referee to a small hole where the ball had entered, but the official was then powerless to overrule his original decision.
He made amends to a certain extent by awarding a generous penalty when Roberto Firmino was fouled a foot outside the penalty area.
Firmino's spot-kick was saved and his rebound hit the post with Omer Toprak striking the rebound back against the woodwork in another dramatic turn of events.
Schipplock managed to head in a consolation, but it came too late to give the home side a chance to get back on level terms.
After Kiessling's 'strike', TEAMtalk looks at three other notable 'ghost' goals.
Clive Allen, Coventry v Crystal Palace, 1980, Highfield Road
Palace striker Allen lashed a powerful free-kick into the top corner of the Coventry goal and saw it smash against the right-hand stanchion before coming out again. However, the officials concluded the ball did not cross the line - and Palace went down 3-1.
Freddie Sears, Bristol City v Crystal Palace, 15 August 2009, Ashton Gate
On-loan West Ham striker Sears was looking for his first goal for Palace when his shot at Ashton Gate flew into the net and then back out again after hitting the base of the goal. Referee Rob Shoebridge consulted with a linesman before awarding a goal-kick and Palace went on to lose the match 1-0.
John Eustace own goal, Watford v Reading, 2008, Vicarage Road
Linesman Nigel Bannister farcically flagged for a goal instead of a corner after the ball crossed the goal-line wide of the goal following a challenge between Eustace and Royals striker Noel Hunt. Despite not a single Reading player appealing for the 'goal' 25-year-old referee Stuart Attwell gave Steve Coppell's men a 1-0 lead.