Teenager Charlie MacDonald scored the only goal of the game to cap a dream full debut as Charlton overcame 10-man QPR at the Valley.

The home side looked to have blown their best chance midway through the second half when Graham Stuart blasted over from the spot, Chris Plummer receiving his marching orders for a second caution as he pulled back Andy Hunt.

But within two minutes 18-year-old MacDonald turned in substitute Shaun Newton's low cross to ensure the Addicks a place in the fifth round.

The first half was a hugely forgettable affair as it took until the 17th minute for the home side to get a shot on target - but even then John Robinson's effort lacked any real power and Lee Harper was able to gather comfortably.

Seven minutes later Hunt's shot was blocked by Jermaine Darlington six yards out after good work on the right by Greg Shields - but again Harper was well positioned to save.

The Addicks' best chance came just after the half hour as Hunt's perceptive crossfield ball found Chris Powell galloping into space.

The full-back charged into the area before unleashing a left-foot shot that Harper could only palm out but John Salako's follow-up was blocked by a tangle of legs in the area.

Mark Kinsella had recovered from a dead leg in time to reclaim his place in midfield but Clive Mendonca's groin strain was not risked with a vital league game at Wolves on Tuesday, meaning there was a second appearance for teenager Charlie MacDonald up front alongside Hunt.

The visitors failed to register a single effort on target in the whole of the first half with the only notable incident the appearance of veteran striker Iain Dowie.

Kevin Gallen limped off after only 15 minutes and with more than a dozen senior players out injured, Rangers' boss Gerry Francis had little option but to call on his assistant manager to replace Gallen up front.

Mercifully the second half started much brighter with Charlton pushing QPR back in their own half for long periods and they almost took the lead in comical circumstances.

Harper wanted one touch too many on Plummer's backpass allowing MacDonald to close in and the keeper was grateful to see his clearance bounce back off the striker and drift inches wide.

Plummer's afternoon then began to go from bad to worse as he was booked for an off-the-ball incident in the 56th minute, one of three QPR players booked in six minutes as they temporarily lost all self-control.

And Plummer's flash of temper was to prove costly on 66 minutes as the game burst into life in a frantic two minute period.

The centre-half was adjudged to have pulled back Hunt in the area and referee Rob Styles had no hesitation in reaching for a second yellow card, followed by a red.

Rangers players protested but to no avail but they were given a reprieve when Graham Stuart blasted wildly over from the spot.

That reprieve lasted less than two minutes however as the home side finally took the lead, MacDonald turning in Shaun Newton's low cross at the near post for his first goal on his full debut for the club.

Newton could have doubled the lead 10 minutes later but hit his shot straight at Harper as Charlton pressed home their numerical advantage.

And at the other end QPR's miserable afternoon was summed up as they appealed in vain for a penalty of their own claiming Hunt had handled in the area, referee Styles not interested despite Gerry Francis' exhortations from the bench.

Teams:

Charlton: Kiely, Shields, Brown, Todd, Powell, Salako (Parker 74), Kinsella, Stuart, Robinson (Newton 46), Hunt, MacDonald (Lisbie 78).

Subs Not Used: Rufus, Ilic.

Goals: MacDonald 68.

QPR: Harper, Darlington (Rowland 79), Baraclough, Plummer, Ward, Bruce, Wardley, Langley, Murray (Scully 69), Steiner, Gallen (Dowie 15).

Subs Not Used: Miklosko, Kulcsar.

Sent Off: Plummer (67).

Booked: Steiner, Plummer, Dowie, Langley, Bruce.

Att: 16,798

Ref: R Styles (Waterlooville).