Southend United were back to winning ways under the lights at Roots Hall as they defeated Brighton & Hove Albion 2-0 in the Checkatrade Trophy Group Stage.
Mooney coolly slotted the Blues in front just past the half-hour mark before Kyprianou stretched the advantage three minutes into the second half.
Next up for Southend is a trip to Bolton Wanderers in Sky Bet League One on Saturday 3 September.
Phil Brown made seven changes to the side that was defeated 2-0 by Fleetwood Town at the weekend, handing a debut to recent signing Anton Ferdinand as the Blues lined up in a 5-3-2 formation.
It was a relatively even start to the game with both sides enjoying spells of possession without the cutting edge to carve out a chance.
The first opportunity of the game came courtesy of the Blues on 20 minutes. White delivering an inviting cross in from the right which Mooney volleyed wide from 12-yards.
Sokolik was then caught in possession two minutes later by Collar on the edge, the ball fell loose inside the area for Ward to latch on to, bringing out a smart save from Smith as he closed the angle.
Kyprianou next to knock at the door, heading just past the post as Southend looked to force an opener on 24’.
The deadlock was broken just past the half-hour mark – Leonard picking the lock of the Seagulls’ defence by sliding in Mooney who slotted past keeper Sanchez comfortably with his right foot; 1-0 Blues after 35’.
That remained the difference as the first half drew to a close with Southend on top.
Half time: Southend United 1-0 Brighton & Hove Albion
Three minutes after the interval, Southend were two to the good as Harry Kyprianou fired in as the ball dropped to him from the left.
Brighton looked to respond quick to that setback as Ward fired over the top after the ball cut back to him in the box on 50 minutes.
Southend could have so easily been three up on 52 minutes at Atkinson marched his way through the Seagulls backline before his shot was deflected wide.
Atkinson was a man on a mission and he charged through again just past the hour mark, this time from the halfway line to the edge of the box before playing it to Cox with the outside of his right. The striker’s effort seemed destined for goal, but was denied superbly by Sanchez.
Ferdinand’s debut came to an end with a standing ovation as he was replaced by Alawode-Williams on 65’ – The defender would be pleased with his first contribution in a Blues shirt, keeping the Seagulls at bay.
With that switch, Alawode-Williams came out to right back at White joined Thompson and Sokolik in the middle of defence.
There was a scare for Southend with 13 left to play as Barclay’s header crashed against the bar after a well-executed ball from the wing.
Back to the other end, and good pressure from Cox and King almost paid dividends as the former’s block almost nestled into the top-left corner, instead just whistling past the post.
Tilley was first to go into the referee’s notebook after a late challenge on John White on the edge on 82’ - The resultant free kick came to nothing.
Blues controlled proceedings late one, seeing out the game well and nullifying the opposition’s threat.
2-0 it finished – a great result to take to Bolton Wanderers at the weekend.
SOUTHEND XI | Smith, White, Thompson, Ferdinand, Sokolik, Kyprianou, Atkinson, King, Leonard, Mooney, Cox.
SUBS | Oxley, O'Neill, McGlashan, Bridge, Williams, Alawode-Williams, Matsuzaka.
Brighton & Hove Albion | Sanchez; White, Goldson, Huenemeier, Cadman; Collar, Hutchinson, Molumby; Hornby-Forbes, Ward, Starkey.
SUBS | Vose (GK), Hall, Barclay, Cox, Tighe, Tilley, Harper.
Attendance | 1,275 (80 Away)