Colchester United make it four points from two away fixtures with the 0-0 draw against the Sky Blues.
The first half was a quiet affair, with the wind preventing too much quality from either side.
Mandron had the only effort that home keeper Lee Burge had to deal with, and it was comfortably done from the header from the U's forward.
His two yellow cards came in the space of a minute, but the U's prevented the hosts scoring in the final fifteen minutes.
McGreal made two changes to his starting eleven, with Doug Loft and Kane Vincent-Young both missing through injury.
Replacing them were Drey Wright and Tom Lapslie, who had both missed recent games with injury issues of their own.
The home side started the game on the front foot, wanting to put Tuesday’s defeat behind them, but despite dominating possession, they didn’t threaten Sam Walker in the early stages.
In fact, those early stages saw both team have two mirror image efforts at goal.
First, a Beavon header went straight at Walker before the same catch was taken at the other end from a Mikael Mandron header.
Mandron then hit a long range effort well over the bar on eighteen minutes, with Michael Doyle following suit for the Sky Blues four minutes later.
The strong wind was having an effect on the quality of passing, especially long balls forward, and chances were becoming fewer as the first half wore on.
It wasn’t until the thirty fourth minute that the next chance came, when Coventry forward Duckens Nazon turned Frankie Kent, beat Tom Lapslie and drilled a low cross across the six yard box.
Walker dived to try and intercept but having missed it, would have been relieved to see that no Coventry player was on hand to tap in.
The half finished with the U’s on the attack, but couldn’t create an opening from a couple of Ryan Jackson throw-ins.
The wind seemed to be even stronger as the teams came out for the second half, and it took a while for either side to test the opposing keeper.
It was on fifty one minutes when Walker was tested, and he managed to tip a right wing cross away from the onrushing Haynes.
The U’s were keeping their shape extremely well, and the home crowd were starting to get restless.
Murray shot wide and Inniss had a header straight at Burge, and it looked like the U’s would be the team to get the first and maybe vital goal of the game.
Comley probably had the best chance, and it was all his own work in the seventieth minute.
He picked the ball up on the edge of the box, bundled is way past a couple of defenders to create some space for himself, but snatched at the left foot shot.
The stand out moment of the game came a few minutes later.
Tom Lapslie was booked for a late challenge in midfield, in the build-up to a Coventry attack that ended with Inniss sliding the ball out for a throw in.
Lapslie then won the ball wide as it was thrown in, was fouled from behind and fell on the ball.
The referee blew for a free kick, not for the foul on the U’s skipper, but for handball.
A second yellow then surprisingly appeared, and the U’s were down to ten men for the remaining fifteen minutes.
Craig Slater came on to fill the gap, with Hanlan making way, and Inniss then made another massively important touch as a Coventry player was poised to shoot.
A minute before the ninety were up, the hosts should have gone ahead, but McNulty completely miskicked when a cross came across the area.
McDonald and Haynes both hit efforts over the crossbar in the four minutes of added time, but the U’s held on for a valuable away point.
It meant that they had gained four in the trips to Newport and Coventry, two teams in the top ten in the League Two table, a great return for McGreal and the squad.