Gary Haines reports from the KC Stadium
Charlton suffered defeat at the KC Stadium on Saturday as Hull City kept their promotion bid on track.
The second-placed Tigers maintained position in the Championship thanks to a 33rd minute goal from Gedo.
The Egyptian striker poked the ball home from close range after a corner from the right had flown through the hands of the onrushing Hamer.
Other than an early booking for a rash challenge, it was the mercurial frontman’s sole contribution of the opening period – but a second goal in as many matches was worth its weight in old gold.
The Addicks, who had seen Dale Stephens clear an early David Meyler effort off the line, mustered little to trouble home keeper David Stockdale in the opening 45.
Charlton fared a little better late on as they pressed for a leveller and Bradley Pritchard fired one good chance wide before Stockdale twice foiled substitute Danny Haynes.
But their winless run stretched to four games as the Tigers dug in late on to preserve their winning margin.
It was Hull that started the game the brighter and only a goalline clearance from Dale Stephens stopped David Meyler from heading them into an eighth minute lead.
Spreading the ball out wide at the earliest possible opportunity, the Tigers targeted the left-sided berth occupied by Cedric Evina but Charlton dug in to quell the danger by hook or by crook and were well in the game going into the second quarter.
Indeed, Hamer had faced just once routine low effort of note before he was beaten shortly after the half hour mark.
And the goal came from a corner as the keeper could not gather the whipped in set-piece from Brady and it was left to Gedo to turn the ball home at the far post.
It was as messy as it gets in terms of a goal conceded as the Addicks fell behind first for the first time in the league since January 1st.
A brave defensive header from Leon Cort foiled Meyler on the stroke of half-time with the Addicks up against it going into the second period.
Meyler was foiled by Hamer again around the hour mark as the hosts continued to forage for more after the break but one good chance did fall the way of the Addicks.
With Robbie Bradley lying injured but play allowed to continue, the ball was moved from Chris Solly to Pritchard via Yann Kermorgant but the midfielder could only prod wide of the post.
Substitute Danny Haynes then saw his instinctive volley from a Pritchard clipped pass fended off by Stockdale, his first real test of the afternoon.
The keeper made a smart close-range stop to foil Haynes five minutes from time as the Addicks finished the game strongly and it was Hamer who prevented a second goal at the death, saving well from sub Tom Cairney with what proved the last act of the afternoon.
In terms of team news Powell made one change as Pritchard returned to the midfield in place of winger Scott Wagstaff.
And the formation changed too with the boss opting to use Lawrie Wilson in a half-and-half role on the right in support of frontmen Yann Kermorgant and Ricardo Fuller.
Pritchard came into a central midfield trio alongside skipper Johnnie Jackson and Stephens in a system familiar to the one that beat Watford on New Year’s Day.
The Hornets, like the Tigers, operated with three central defenders so the gameplan was to stop them playing out.
Hamer was again between the posts for the Addicks with the backline completed by full-backs Chris Solly and Cedric Evina and central pairing Michael Morrison and ex-Tiger Leon Cort.
The midfield trio were supported by Wilson, Kermorgant, expected to drop to the left to back up Evina, and Fuller.
Wagstaff dropped to the bench where he was joined by David Button, Matt Taylor, Dorian Dervite, Rhoys Wiggins, Bradley Wright-Phillips and the fit-again Danny Haynes.
The hosts dropped Slovenian star Robert Koren to the bench as Egyptian striker Gedo started for the first time alongside Jay Simpson.
There was also a recall in a holding midfield role for Alex Bruce, son of home boss Steve while enterprising wing-backs Ahmed Elmohamady and Robbie Brady were potential threats going forward.
On a tricky surface it was the Tigers that got their teeth into proceedings the quicker, doing their best to double up against Evina on the right and Morrison produced two timely touches as balls came in from that flank.
And in the eight minute there was a let off for the visitors as Stephens cleared off the line to foil David Meyler.
Kermorgant, like most of the other black-shirted Addicks, appealed for offside after a half-cleared free-kick, but play continued and the cross reached Meyler whose header was cleared away by the well-placed Stephens as the natives sucked the ball over the line.
The danger was not fully cleared by centre-back Jack Hobbs put the loose ball wide as the Addicks drew a sizable sigh of relief.
A rash challenge from Gedo sent Solly sprawling and earned the home striker a booking on the quarter hour.
After Fuller picked out Jackson to his left the hosts just about smuggled the skipper’s cross clear as a cluster of Londoners waited in the middle.
Jay Simpson’s daisy-cutter gave Hamer his first save of the afternoon midway through the half while Hull had to be on their guard again as Pritchard cross was nodded back by Kermorgant with James Chester on hand to clear the danger.
But it was the hosts that claimed the lead in the 33rd minute through Gedo.
After Jackson got back well to turn the ball behind for a corner ahead of Elmohamady, the flag-kick bypassed Hamer, who came to claim through a cluster of bodies and Gedo, stationed on the left side, forced the ball over the line from close range.
Having worked so hard in the opening third of the game the concession was a bitter pill to swallow for the Addicks. And not only was Fuller’s appeals to win a free-kick on the left side of the box turned down soon afterwards, the Jamaican was booked shortly after receiving treatment, presumably for dissent.
In the first added minute at the end of the opening period Hull got round the back on the left after a clever exchange of passes and after the cross bypassed traffic in the box, it eventually reached Meyler whose fearsome drive was headed up and behind bravely by a defiant Cort.
The Addicks negotiated the subsequent corner, the last act of the half, but went in behind at the break.
After a quick corner two minutes after the restart Elmohamady’s dangerous low centre flashed across the face of goal and wide and Hamer was quickly off his line to snare the ball after Evina’s chest-back fell short.
Bradley blasted a free-kick over after a foul from Jackson on Quinn, which earned the visitor a booking.
McShane’s afternoon was over after he pulled a hamstring hunting down Fuller deep in his own half so Ahmed Fathi came on in his place.
After the Addicks forced a corner, Fuller headed Jackson’s centre just over as the hour mark approached.
The Tigers still carried more bite going forward, and after an Elmohamady cross was nodded back, Meyler was again in space on the edge of the box with his stinging drive batted down and claimed by Hamer.
After yet another cross from the right, Gedo headed off target while at the other end, after Brady writhed in agony after a challenge with Wilson play was allowed to continue.
Solly drove forward from the right and Pritchard burst onto Kermorgant’s neat touch but could only stab a big chance wide of the left post.
Haynes entered the fray for Fuller entering the final quarter of the match and Robert Koren replaced Simpson for the hosts soon after.
Charlton almost levelled straight away, however, as Pritchard chipped a ball into the box and Haynes flashed a volley straight at Stockdale. It was an instinctive hit from the striker but either side and the ball may well have nestled in the back of the net.
A quite incredible decision from the match officials then conspired to give the hosts a corner after Hamer had repelled Gedo on the left, but the keeper retained his composure to deal with the comer as another cross into the box was cleared.
Wilson made way for Wright-Phillips in the closing 10 minutes with Koren lifting an effort off target for the hosts after spotting Hamer off his line.
After Koren picked out Gedo on the right the Egyptian’s cross was headed wide firmly on the run by Meyler.
Wright-Phillips hooked the ball in the back of the net after fouling Stockdale, so a free-kick went the way of the hosts, but the keeper was pressed into action five minutes from time when Wright-Phillips flicked the ball on for Haynes whose close-range effort was turned behind for a corner.
That flag-kick was headed off target by Morrison and Powell’s last roll of the dice was to introduce Dervite for Evina in stoppage time, of which there were four minutes.
Also entering the fray was Tom Cairney for Gedo and the hosts almost banked a second at the death as the newcomer burst into space but was denied by a superb stop from Hamer.
It proved the last touch of the game as the Tigers marched on and the Addicks were faced with an arduous trip home with nothing to show for their efforts.
Charlton: Hamer; Solly, Evina (Dervite 90), Cort, Morrison; Stephens, Pritchard, Jackson, Wilson (Wright-Phillips 80), Kermorgant, Fuller (Haynes 68).
Subs (not used): Button, Taylor, Wiggins, Wagstaff.
Booked: Fuller 39 (dissent), Jackson 51 (foul on Quinn)
Hull: Stockdale; Chester, Hobbs, McShane (Fathi 56); Elmohamady, Bruce, Meyler, Quinn, Brady; Gedo (Cairney 90), Simpson (Koren 70).
Subs (not used): Jakupovic, Rosenior, Evans, Proschwitz.
Booked: Gedo 15 (foul on Solly)
Goal: Gedo 33
Referee: S Mathieson
Att: 16,849 (692 Charlton)