Aidy Boothroyd’s side had already suffered two defeats on the road and been reduced to ten men in both games with the manager calling on his side to be smarter in their approach to away fixtures while also looking for a response to the home reverse against Torquay United.
"In the first few games we've beaten ourselves, which is irritating from a managerial point of view,” he told BBC Radio Northampton prior to the game.
Opponents Rovers gained a first win of the season at home to York last weekend and were looking to push on from that with manager John Ward warning his side that Town would be ‘fired-up’ for the clash.
Clive Platt and Roy O’Donovan were paired up front for the Cobblers while new signing Matty Harriott was on the bench.
1st Half: Town got off to the worst possible start when Lockyer scored within 2 minutes for the hosts, who carried their lead into half-time.
2nd Half: No joy for the Cobblers in their quest for an equaliser and once again they ended up with 10 men after O'Donovan's stoppage time sending-off.
Reaction: Fury from Boothroyd as he blasted referee Mark Haywood's failure to award his side one of three possible penalties.
"Points are at stake here and we want to win games, but at the minute we are not getting the decisions, and we are certainly not getting that bit of luck that you need."