A late red card confounded a frustrating day at the Riverside Stadium as Charlton fell to a 1-0 defeat at the hands of Middlesbrough.
Rhoys Wiggins was shown a straight red for a dangerous challenge with six minutes remaining as any hope of points slowly faded away despite an encouraging second-half performance in the north east.
And it was a speculative first-half shot which beat the Addicks, with debutant goalkeeper Yohann Thuram-Ulien caught out by Emmanuel Ledesma's awkward 30-yard drive.
The goal went unanswered by Charlton as they were left to suffer another single-goal defeat on their travels.
As far as the team news went, there was plenty of talk in the run up to the game about who may start between the sticks.
With Hamer making a starting return from injury in midweek against Oxford United, he suffered a setback before the trip to the Riverside Stadium meaning he would miss out.
And with Ben Alnwick falling ill pre-match, new signing Thuram-Ulien was given the nod to make his Addicks' debut.
The reshuffling between the goalkeepers gave an opportunity to academy product Dillon Phillips who appeared on the bench for the first time alongside Thuram's fellow Standard Liège loanee, midfielder Astrit Ajdarević.
Elsewhere, Powell opted for a 4-5-1 formation as Callum Harriott was handed a first start since the defeat at home to Leeds United in November while Jordan Cook made only his second league start in a Charlton shirt with providing the threat out wide in support of Yann Kemrorgant.
Charlton got in round the back of Middlesbrough's defence early on with just 90 seconds on the clock.
Harriott carved the hosts open before his attempted lay-off to Cook bounced off a Boro player after a defensive mix-up.
But with the ball falling into the path of Kermorgant, the Frenchman scuffed his shot wide from 12 yards.
And the home side responded with a chance of their own.
Curtis Main ran free after Lawrie Wilson misjudged a high bounce and after Michael Morrison's attempted tackle bounced straight back to the striker, he bent a shot narrowly wide from the edge of the box.
Shortly after, the ever-dangerous Marvin Emnes threatened with an angled shot from the right which could only bulge the side-netting.
Middlesbrough had come the closest in the opening exchanges and on 16 minutes they went up front.
With Ledesma picking up possession some 30 yards from goal, the Argentine let fly with a low shot which bounced it's way past Thuram-Ulien and into the back of the net.
In truth, the loanee stopper could, perhaps, have done better to read the effort which bounced awkwardly just in front of his dive to the left.
As it was, the Addicks were behind, and they had a game to chase.
An immediate response very nearly came in the unlikely form of Morrison.
The defender was in an advanced position as he got on the end of Harriott's ball over the top but just couldn't adjust as veteran 'keeper Shay Given collected and won a foul from Morrison's challenge.
Due to the nature of Boro's opener, it became clear that they had identified a potential Achilles heel and fancied their chances from range.
Mustapha Crayol was next to try his luck and his drive moved in the air forcing Thuram-Ulien into a save with his feet.
Emnes, meanwhile, bent a follow-up straight into the arms of Thuram-Ulien and Charlton could breathe again.
Both sides looked handy going forward in the first-half but the home side were shading the midfield battle.
The Addicks came close to drawing level five minutes before the break when Dale Stephens swung in a dangerous corner from the left.
With Johnnie Jackson rising highest, he was a hair's breadth away from a connection from six-yards but Given got an all-important fingertip on it first to clear away.
With the two sides retreating for the interval Aitor Karanka would be the happier after a tight first-half and Charlton would have it all to do in the second period.
Powell switched things round at half-time, moving to Cook to a more central role alongside Kermorgant with Stephens moving out wide.
But it was Middlesbrough who fired the first shot of the second-half.
With Main getting the better of Wilson, he cut into the box before pulling back for Dean Whitehead.
But the midfielder saw his shot go high and wide with Thuram-Ulien left unfazed on that occasion.
Richard Wood was presented with a glorious chance on 52 minutes.
With a free-kick being delivered on the right-flank, Wood was on the end of a knock down as he lurked around the penalty spot.
But the centre-backs could only divert his shot agonisingly wide of Given's right-hand upright.
Charlton looked a much improved side following the interval but it was all about carving out that decent opportunity to draw level and as yet, it simply hadn't come.
Down the other end, Mustapha Crayol went on a mazy run which the Addicks just could not stop.
As he jigged his way into the box, the wide man unleashed an effort which drew Thuram-Ulien into a good, leaping save.
Powell attempted to inject some impetus into his side with a double change in the 67th minute.
Simon Church swapped with Cook to join Kermorgant up front and Danny Green replaced Jackson hoping to build on his impressive cup cameo against Oxford.
On 70 minutes the Addicks thought they had drawn level.
Green, once again, made an immediate impact as he raced down the right.
His deep cross was kept in against all odds by Kermorgant and, hooking the ball back across goal, the ball was bundled in by Church who appeared to get to the ball first before Given.
But any joy was quelled straight away by the referee's whistle who deemed Church's header as a foul on the former Republic of Ireland custodian.
It was the sort of decision which leaves you questioning the level of protection goalkeepers receive in those situations. But rightly or wrongly, the goal was disallowed.
The last throw of the dice came in the form of Ajdarević who entered the fray in place of a tiring Jordan Cousins with 13 minutes left on the clock.
But the Addicks added to their own downfall in the 84th minute when Wiggins' dangerous challenge saw the left-back sent for an early bath.
Going in for a loose ball with Whitehead, Wiggins went in too high which gave referee Keith Stroud no choice but to brandish the red card.
Any remaining piece of strength Charlton had seemed to have disappeared down the tunnel with Wiggins but they would muster a final attack in search of what would have been a vital point.
Kermorgant crossed for Church in injury-time, but with the ball flashing across the six-yard box, Stroud pulled play back for a late tackle on the striker.
And from the set-play the ball was teed up for Wilson who's viscous drive flew just wide.
There was still time for Thuram-Ulien to produce a fine save one-on-one from Whitehead at the other end before Stephens was presented with a chance with the last kick of the game.
Picking up the pieces after Boro failed to clear a cross, the midfielder fired a half-volley towards goal with Given seemingly stranded.
But the 'keeper made a miraculous, match-winning save, clinging on to the ball with his life and thus, clinging on to all three points.
With that, a frustrating game on Teeside came to an end and the Addicks, not for the first time this season, would be left to curse their luck.
Charlton: Thuram-Ulien; Wilson, Wiggins, Morrison, Wood; Cook (Church 67),Cousins (Ajdarević 77), Stephens Jackson (Green 67), Harriott; Kermorgant.
Subs (not used): Phillips, Hughes, Evina, Dervite.
Sent off: Wiggins 84 (foul on Whitehead)
Boro: Given; Varga, Ayala, Williams R, Friend; Ledesma, Leadbitter, Whitehead, Carayol ( Kamara 88); Emnes (Jutkiewicz 57), Main (Smallwood 79).
Subs (not used): Konstantopoulos, Butterfield, Gibson, Woodgate.
Booked: Ledesma 81 (foul on Harriott), Whitehead 82 (foul on Kermorgant), Ayala 92 (foul on Kermorgant)
Goals: Ledesma (16)
Referee: Mr K Stroud
Att: 14,548 (258 from Charlton)