Brentford boss Mark Warburton is confident his side will still get automatic promotion despite a 1-0 defeat to Swindon.
The Bees are seven points clear of third-placed Leyton Orient after Louis Thompson's first-half goal sealed the win for the Robins.
Thompson coolly fired past David Button after 45 minutes after Jonathan Douglas had given the ball away.
The home side should have taken the lead earlier but Michael Smith saw his penalty saved by goalkeeper Button.
After the setback, Warburton said: "There's plenty of football left yet for us to get that second promotion place.
"It was frustrating we gave the goal away just before half-time as we were in charge of the game at the time.
"We paid the price for a poor defensive decision, but I thought that we bossed it in the second half. We got behind them and got in some good positions but missed our chances and we weren't good enough on the day.
"There were a lot of positives from our perspective though and some of our play was excellent and I've got no complaints.
"We knew Swindon would ask us a lot of questions and were aware of the challenges they would pose. They were feisty, good quality, good technical players."
Brentford played the last half an hour or so with 10 men when Adam Forshaw got two yellow cards in the space of 90 seconds.
The away side still missed chances to equalise through Alan Judge and James Tarkowski but Nathan Byrne also should have doubled his side's advantage.
Swindon goalkeeper Wes Foderingham then produced a superb one-handed save to deny substitute George Saville late on but the Robins held on to move up to seventh in the table.