Di Canio ended a turbulent week for him personally by taking a stretcher ride back to the dressing room after being carried off in the 70th minute. Following a challenge by Scott Parker, the Italian waved agonisingly towards the bench before being taken off amid fears that he may have suffered medial ligament damage to his left knee.
Di Canio, who caught his studs in the turf, was set to go to hospital for a scan.
But the Italian had followed his latest public outburst, having been substituted at Fulham the previous Monday, by winning the 22nd minute penalty and then scoring from the spot himself.
Di Canio further capped his dramatic 100th appearance for the Hammers by helping to set up Hammers' second in the 33rd minute, passing to the overlapping Sebastien Schemmel who pulled his byline cross back for Kanoute to sweep home from eight yards.
The West Ham skipper might have been surprised by referee Mike Riley's penalty award after going down under a challenge from Graham Stuart and Scott Parker. Charlton boss and former Hammer, Alan Curbishly, felt it was contentious. It was Riley, remember, who induced that fit of pique by Di Canio when the official waived away a succession of penalty appeals against Bradford City at Upton Park two years ago.
The result didn't reflect Charlton's second half dominance. David James, who didn't make his first serious safe until he denied Stuart from 18 yards in the last minute of the first half, was by far the busier of the two keepers after the interval.
Jonatan Johansson had headed against a post at the end of a rare Addicks attack in the 37th minute and the visitors were denied by the woodwork again when Mark Kinsella rapped a shot against the crossbar five minutes into the second half.
Hammers were in showboating mode by then. Joe Cole, in particular, Di Canio and Trevor Sinclair delighted the 32,389 crowd, who needed warming up on a sunny, yet chilly afternoon, with their array of clever flicks and tricks. It was entertaining stuff but Charlton keeper Dean Kiely didn't have to make a save in the second half until Cole drove a shot at him in stoppage time.
Even Roeder jumped on the entertainment bandwagon, raising a large cheer from the crowd with a neat flick of the ball to Schemmel as the Frenchman went to retrieve it for a throw-in!
Hammers' failure to go for the jugular gave Charlton prolonged hope of a fightback but they found James in defiant form. The Addicks also wasted their best chance when Paul Konchesky blazed his 71st minute penalty high over the bar at the Centenary Stand end after Nigel Winterburn had fouled Johansson.
Although they always looked dangerous on the break, with Michael Carrick orchestrating much of the play from midfield, Hammers couldn't penetrate in the second half. Even Jermain Defoe, who replaced the injured Di Canio, didn't get a sniff of goal against the club where he began his young career.
West Ham's best effort of the second half came on the hour mark, when Sinclair cut in from the left flank and struck a low, angled drive that hit the outside of the near post.
The game ended with the extraordinary appearance of John Moncur, who, subbing for Cole, was on the pitch just four seconds before Riley blew for full-time. And no, he wasn't booked either!
Minute-by-minute:
2 - Repka's header from Di Canio's early corner drifts wide of the target and out for a goal kick.
11 - After Schemmel's attempted pass to Kanoute is blocked by a defender, Cole picks up the loose ball and skips into the box before firing in a low right foot shot that Kiely holds well.
13 - Konchesky's inswinging corner from the right catches the wind and is misjudged by James, but Lomas is on hand to clear.
18 - After Lomas fouls Parker, Konchesky's low free-kick from 30 yards out is comfortably gathered by James.
21 - Di Canio's right-foot effort from just outside the box sails wide of the target.
23 - Hammers are handed a glorious chance to take the lead as Di Canio takes advantage of Rufus' lapse in concentration and wriggles into the box before being sandwiched by Stuart and Parker. Referee Riley immediately points to the penalty spot.
24 - GOAL! Di Canio dusts himself down to confidently stroke the ball home from 12 yards. West Ham United 1 Charlton Athletic 0.
29 - Fortune booked for a foul on Cole.
30 - Cole's flick almost finds Lomas in the six yard box but Kinsella's magnificent last ditch tackle clears the danger.
34 - GOAL! James sets up a fantastic flowng move that sees Cole find Kanoute, who in turn reaches Di Canio on the right. The Italian's overhit pass for the overlapping Schemmel appears to be heading out of play, but the Frenchman pulls it back from the byline for Kanoute to blast home from eight yards out. West Ham United 2 Charlton Athletic 0.
34 - Kiely booked for dissent.
37 - Carrick almost rounds off another fantastic move as he receives a return pass from Kanoute but shoots just wide.
38 - Konchesky's right-footed cross finds Johansson, whose header crashes back off the post and is cleared by Repka. The reaction of the Bobby Moore Stand suggests that James got a saving hand to the effort.
39 - Lomas booked for a foul on Parker.
40 - Kinsella booked for a foul on Cole.
42 - Sinclair attacks on the break again and runs almost the entire length of the field before squaring the ball to Di Canio, who takes one touch too many and is crowded out in the penalty area.
44 - James bravely punches a corner clear to the edge of the area and then combines with Sinclair to keep out Kinsella's low shot.
45 - Our England keeper once again proves his quality with a fantastic one handed save to tip over Stuart's blistering shot from the edge of the area.
Added time: 1 minute.
Half-time: West Ham United 2 Charlton Athletic 0.
Second Half:
46 - Carrick almost hits a goal of the season contender in the first minute of the half as he collects the ball in his own penalty area and gallops the entire length of the field but sees his left foot shot blocked by a defender.
49 - Repka dallies on the ball in his own area and then loses possession to Konchesky, who hammers in a left-footed shot that crashes against the side-netting.
50 - Another Konchesky effort is blocked by Schemmel, and Stuart's follow-up shot is well held by James.
51 - Charlton come even closer as they begin to take a grip on the game, with Kinsella rattling a right-foot shot against the bar.
55 - Costa booked for a foul on Sinclair.
63 - The woodwork once again comes into play, as Sinclair's thunderous low shot from the edge of the area cannons off the post and out for a goal kick.
66 - Kinsella's dangerous cross from the right is headed out for a corner by the alert Repka.
67 - Di Canio is left in a crumpled heap on the ground, clutching his calf after Parker's challenge. The Italian receives three minutes of treatment before leaving the field on a stretcher.
70 - Substitution for West Ham, Defoe replaces Di Canio.
71 - Amazing scenes in the Hammers penalty area, as Carrick's clearance rebounds against a Charlton player and hits the post before bouncing across the six yard box. As Johansson follows up, Winterburn appears to win the ball with a sliding challenge, but referee Riley points to the penalty spot once again to hand Charlton a lifeline.
72 - A let-off for the Hammers as Konchesky blasts his spot-kick high over the bar.
77 - Parker's shot from the edge of the area is again superbly tipped over by James.
80 - James again provides an unbeatable barrier as he holds Johansson's snap-shot from 20 yards out.
85 - Stuart's chip at last beats James - but lands on the roof of the net.
90 - James pulls out another impressive save to deny Euell's low effort.
Added time: 3 minutes.
90 - Schemmel releases Cole, who fires in a shot that is well saved by Kiely.
90 - Substitution for West Ham, Moncur replaces Cole.
Full-time: West Ham United 2 Charlton Athletic 0.
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