Gary Haines reports from St James' Park
Charlton opened up a nine-point lead at the top of League One after seeing off Exeter City 1-0 on Saturday.
A freak goal from Danny Green sealed three precious points in Devon as the Addicks completed a fourth successive victory.
The winger's 55th-minute cross from the right deceived home keeper Arthur Krysiak and eventually bounced over the line after some fumbling from the Pole.
The post was also rattled before the ball crossed the line and Green wheeled away to celebrate what he believed was a third goal of the season.
Whoever is credited with the goal in the final shake-up, it will matter not for Chris Powell, whose side has yet to concede in the league in 2012.
Their resolute run now stands at seven hours and five minutes after another durable defensive display in Devon.
It was another hard-working display from the Addicks against a home side who probed, hassled and harried but couldn't find a way through.
A well-protected Hamer did make a couple of notable stops in a second half that was far more action-packed than a cautious opening period.
The best chance in the opening stanza actually came when ex-Grecian Matt Taylor's overhead kick was cleared off the line.
Taylor and his rearguard stood strong at the other end with some key blocks and interceptions - and in truth the more clinical side in the final third were the visitors.
Yann Kermorgant's bullet diving header was just wide while substitute Leon Clarke also ruffled the side-netting late on.
There was also a welcome late cameo for the back-to-fitness Dale Stephens on a day that was bettered when news of Huddersfield Town's 1-1 draw at Tranmere Rovers filtered in.
The gap now sits at a healthy nine points - and the lead to the automatic promotion places is up to 10. It will be a happy trip home for the Londoners.
In terms of team news, Charlton named an unchanged side. Fresh from their impressive wins against the two Sheffield clubs in the past two League One encounters, Chris Powell resisted the temptation to make changes ahead of the clash in Devon.
There was a return to the bench for Stephens following his midweek outing in the Kent Senior Cup at Margate while Johnnie Jackson skippered the side fresh from his successive free-kick winners against the Owls and the Blades.
There were reunions too for former Grecians defender Taylor and keeper Hamer, who spent time on loan at St James' Park last season.
Hamer continued between the posts for the visitors behind the regular rearguard of full-backs Chris Solly and Rhoys Wiggins and central pairing Taylor and Michael Morrison.
Jackson, having moved on to 10 goals for the season thanks to his set-piece specialties against the Steel City rivals, lined up on the left with Green on the right.
Danny Hollands was joined by Bradley Pritchard in the engine room.
Up front was Bradley Wright-Phillips, whose Plymouth Argyle connections ensured he would get a warm reception from the home crowd, and Kermorgant.
John Sullivan was the back-up keeper on the bench where he was joined by Leon Cort, Stephens, Danny Haynes and Clarke, the latter having netted twice in the midweek 4-3 win at Margate. Darel Russell sat out the first of a three-game suspension.
The hosts made two changes as former Addicks triallist Guillem Bauza and Richard Logan dropped to the bench.
Scot Bennett and striker John O'Flynn came in to the starting line-up while former Charlton reserve man James Dunne was in midfield in hat started as a 5-3-2 line-up.
After a ninth minute pass offered O'Flynn half a sight of goal, but Wiggins mopped up the danger,
At the other end Taylor almost opened the scoring against his old club two minutes later.
The centre-back was still up after a cleared throw from Danny Green, and as the ball came back across, he connected with an overhead kick which was sliced off the line by Richard Duffy.
An Addicks free-kick bounced straight through and behind for a goal-kick moments later, promoting a touch of anguish amid the home fans.
O'Flynn's header from a left-wing cross was comfortably pouched by Hamer and David Noble's curling free-kick landed in the packed away end after 17 minutes after he was upended by Hollands.
There was a change of ball after Jake Taylor headed a clipped Dunne cross well off target while two corners from the Addicks came to nothing at the start of the game's second quarter.
Artur Krysiak, under pressure from Kermorgant, fumbled a curling free-kick from Jackson on 33 minutes, and the skipper toe-ended a Wright-Phillips clipped centre soon after but the keeper saved.
Wiggins bore forward and saw his low angled drive saved at his right post by Krysiak, before Exeter almost cashed in on a controversial call.
After what looked like a hand-ball from Jake Taylor, Morrison stopped waiting for a whistle that never came.
It allowed Taylor to get in position to shoot, but he lifted his shot over as Morrison offered his opinions to the referee.
Pritchard skied a volley from the right edge of the box but clear-cut changes were still few and far between.
Dune never really controlled a bobbling ball before shooting high over the bar in the last minute of the half after Pritchard had been caught short in midfield.
Morrison got in a timely header at a whipped in cross from the left, with O'Flynn ready to pounce, and that proved the last action of the half.
Noble warmed the gloves of Hamer with a shot from range three minutes after the restart and Coles got in ahead of Wright-Phillips to make a timely challenge as the clock reached 50.
It was an important challenge as the striker licked his lips and a clever head down from Kermorgant allowed Hollands to find Jackson on the left and his cross fizzed dangerously across the face of goal and wide.
Smart defending from Solly foiled Jake Taylor - but the deadlock was broken 10 minutes in.
Green collected the ball down the right channel and worked himself into a crossing position - but he did so much better.
As Krysiak got his starting position all wrong, the ball sailed towards the near post and eventually went over the line via the desperate gloves of the Polish keeper and the post.
Quite who will actually claim the goal remains open to question - Kermorgant was also lurking behind him - but it will not matter a jot to the gleeful fans behind the goal.
On came Logan and Bauza before the restart and a Scott Golbourne free-kick caused problems for Hamer before dropping behind for a corner.
The same player's flag-kick cause more hassle for Hamer as the Addicks rode their luck but - they almost doubled their lead on 63 minutes.
Wright-Phillips was the architect and his fine cross from the left was headed just wide on the middle by Kermorgant.
It was a firm header, and the only surprise to the Addicks fans was that it was not on target.
Bauza leapt to steer a header in midway through the half, but Hamer plunged to tip the ball round the left post and behind for a corner.
The keeper saved well, plunging once more, to foil Bauza, before Logan was guilty of an awful miss on the follow-up.
Luckily for him the flag went up for offside, semi sparing his blushes, and Clarke then replaced Wright-Phillips on 71 minutes.
Wiggins blocked a half-effort from Nardiello before Green made way for the returning Stephens.
There was a flutter of anxiety as a Golbourne shot was shot on the turn by Bennett but an offside flag was again raised as Hamer saved well.
Clarke shot wide from the right side of the box before Haynes came on for Pritchard a minute from time.
There was a late booking for Wiggins after he slid to win the ball on Tully, and Taylor got in a timely block to avert a Bauza shot right at the death.
The ball rolled back to Hamer and the keeper's clearance proved the last kick of the game as the Addicks toasted a fourth successive win.
Charlton: Hamer; Solly, Wiggins, Taylor, M Morrison; Green (Stephens 82), Hollands, Pritchard (Haynes 89), Jackson; Kermorgant, Wright-Phillips (Clarke 71).
Subs (not used): Sullivan, Cort.
Goals: Green 55
Booked: Hollands 81 (foul on Bauza), Wiggins 90 (foul on Tully)
Exeter: Krysiak; Tully, Golbourne, Duffy (Bauza 56), Archibald-Henville, Coles; Dunne, Noble, Bennett; Taylor (Nardiello 64), O'Flynn (Logan 56).
Subs (not used): Pidgeley, Jones.
Referee: G Salisbury
Att: 5,439 (828 Charlton)
