Massimo Luongo was the hero and the villain for Swindon Town as they were pegged back by a late penalty in the first leg of their League One semi-final playoff at the County Ground.
He broke the deadlock in the 70th minute, but conceded a penalty in the last minute of added time to cost his team victory.
After a cagey opening 20 minutes, it was Gary Roberts who had the first attempt on goal, but his long-range effort was deflected over the bar.
Brentford nearly took the lead themselves moments later when Adam Forshaw shot just wide after latching onto Bradley Wright-Phillips's through-ball.
Adam Rooney could have put the Robins ahead when he was played one-on-one with Simon Moore, but the goalkeeper kept his side on level terms.
Jonathan Douglas then had a go from the edge of the box, but his effort drifted wide of the far top corner.
It took until the 70th minute before Luongo's clipped right-footed shot went beyond a despairing Moore to send the home fans into raptures.
Alan McCormack and Rooney had chances to further extend the lead, but both times Brentford got men back to put the block in.
Farid El Alagui was denied down the other end by a last-ditch tackle from McCormack after he made a drive into the box.
Just as it looked as if the hosts would hold on for the first-leg lead, Luongo chopped down Sam Saunders and the referee had no choice but to point to the spot.
Kevin O'Connor stepped up and he coolly dispatched the ball past Wesley Foderingham to seal a draw for his side.