Gillingham boss Neil Harris cut a frustrated figure after his side failed to build on their promising first-half display at League 2 leaders Leyton Orient on Tuesday night.

The Gills edged a tight first half in east London, the manager producing a tactical master-stroke with a 4-3-2-1 formation that stifled the home side.

But they conceded early in the second half and never really looked like getting back into the contest before letting in a second goal with just under 20 minutes remaining.

“Firstly, I’d like to thank the fans for their input tonight, they were magnificent,” said Harris, with more than 900 Gillingham supporters making the trip. “They deserved more than a defeat.

“First half I thought we were outstanding. We changed shape, we had a game-plan, we nullified them, we were excellent without the ball. We were good with the ball and we should have been in front. Again, we just haven’t scored, have we?

“The frustration for me as the manager is I [couldn’t] sign the players that I wanted in the summer, it comes back to bite us again. Then two really poor goals to give away, as you can tell I am fuming. On the back of the first half to concede goals like we did was not acceptable.”

Gillingham restricted Orient to three off-target attempts in the first half, and they could have easily gone ahead.

Skipper Stuart O’Keefe had their best opening but he hesitated with a clear sight of goal and eventually hit shot turned into a cross which was blocked by the home side.

“Glenn [Morris] has hardly touched the ball in the first half apart from the times we passed it back to him and made him kick it from his goal line,” noted Harris. “Other than that he hasn’t touched the ball with his hands, he hasn’t had to make a save and they’ve had one half-chance they put wide. (For us, Stuart O’Keefe) has to score, bottom line.

“Don’t get me wrong, Orient are top of the league for a reason - they are a good team. [They’ve] excellent experience defensively and at the top end of the pitch they’ve got game changers, they’ve got players that can beat you one v one and put the ball in the back of the net.”

Gillingham’s best chance fell to Elkan Baggott in the second half but he blazed over after Will Wright’s long-range shot was beaten away.

Harris couldn’t fault his team’s efforts but knows they lack a clinical edge in attack.

“I don’t want to sound damning on my group because I’m not,” stated Harris. “I’m really proud of the first half performance but if I want to drive standards to be better then I need better in the second half.

“Elkan was 20 during the week, he’s scored two in two and the best chance of the game probably has fallen to his feet, an empty goal and it’s the composure.

“The good thing is we’ve played the best team in the league with one of the best defensive records and we’ve made chances.

“I can’t fault the players’ effort and the fans stayed to clap them off the pitch because of the effort they put in but we gave two poor goals away.

“You play top of the league away from home, you can’t be that good for 45 minutes and then give two really poor goals away. When your chances come, you have to be ruthless. It’s a clinical nature, I keep talking about being better at the top end of the pitch.

“We’ve scored six games in a row, and were seven games unbeaten - that’s brilliant. When you come to the top of the league, you have to be even better. For 45 minutes we were and then we fell apart second half and gave two poor goals away, it’s not acceptable.”