Morgan opened the scoring in the sixth minute and the Chairboys were the better side in the opening period, but the visitors improved after the break and secured the points through Barry Corr and Britt Assombalonga.
Gareth Ainsworth made two changes with Matt Spring and Dean Morgan coming into the side. Spring replaced Marvin McCoy with Michael Harriman reverting to right-back, while Morgan was in for Jo Kuffour.
Southend started well, but it was Wanderers who had the first shot when Morgan latched on to a ball over the top, but shot wide from a tight angle.
Ainsworth’s men took the lead in the sixth minute and it came at the end of a fine move. Sam Wood fired the ball low and hard into Matt McClure who held it up before laying off to Morgan who curled home right-footed from the edge of the area.
McClure had a shot of his own in the 12th minute, but his 20-yard strike went high and wide of Paul Smith’s goal.
Britt Assombalonga thought he had levelled in the 15th minute when he tapped in Barry Corr’s knock-down from Kevan Hurst’s free-kick, but his celebrations were short-lived due to the assistant flagging for offside.
Charles Dunne came close to getting a good connection on Joel Grant’s right-wing cross, but he was nudged underneath the ball and his header looped into the air.
Jodan Acher was called into action for the first time in the 21st minute when he parried Hurst’s powerful drive before collecting at the second attempt.
Dave Winfield headed Spring’s corner wide, before Michael Spillane lashed over the bar whilst under pressure in the area following Ryan Leonard’s long throw-in.
Winfield reacted first to another Spring corner in the 28th minute, but his shot was blocked by a line of Southend defenders. Spring’s set-pieces caused havoc in the away side’s defence throughout the first half and Winfield headed another one over from 10 yards.
Assombalonga threatened the Wanderers goal again in the 35th minute when the on-loan Watford striker cut inside Winfield, however, he mishit his shot and Archer made a comfortable save low to his left.
Blues started the second half well with Morgan crashing a 20-yard strike over the bar, but the visitors drew level eight minutes after the restart. Hurst’s corner was met by Cresswell and Corr reacted quickest to his knockdown and fired home.
McClure almost restored Chairboys’ advantage three minutes later but his powerful shot hit Luke Prosser in the face and rebounded to safety.
The visitors came even closer in the 58th minute when Hurst’s corner was cleared as far as former Wycombe loanee Anthony Straker who took aim from 30 yards, only for his effort to crash back off the bar. Archer then produced a fine save low to his left from Corr who shot across goal from eight yards.
Archer saved again from Corr in the 63rd minute after the striker met another Hurst corner, before Morgan volleyed over from the edge of the area.
Chances were few and far between at the start of the second half for the Blues, but Wood should have done better when he volleyed wide after Morgan had flicked on Grant’s lofted pass. It was an excellent opportunity for Wycombe with the Southend defence cut open.
Southend’s Sean Clohessy did superbly well to head McClure’s header off the line with six minutes remaining as Kuffour was lurking at the far post and ready to tap home.
And the visitors took full advantage of that clearance a minute later when Assombalonga collected Hurst’s flick, cut in from the right and drilled into Archer’s right-hand corner.
Smith produced a superb save in the 87th minute to deny McClure an equaliser after Winfield’s acrobatic volley had fallen for the striker in the area. McClure’s left-footed effort from six yards looked destined for the far corner, until Smith somehow got a hand to it to parry away.
Wanderers piled on the pressure, but the Southend defence held firm to take the points.
Wanderers: Archer, Harriman, Dunne, Winfield (c), Stewart, Grant (Andrade 88), Lewis, Spring, Wood, Morgan (Kuffour 76), McClure.
Subs: Harrison, McCoy, Hause, Ainsworth, Oli.
Southend: Smith, Clohessy, Barker (c) (Straker 38), Cresswell, Prosser, Mayor (Reeves 76), Hurst, Spillane, Leonard (Lund 76), Corr, Assombalonga.
Subs: Bentley, Woodyard, Eastwood, Harris.