Greece came from behind to defeat Nigeria in a pulsating match that kept alive their hopes of qualifying from Group B.
It was the first victory for Greece at a World Cup and came after a contest that was completely transformed by the dismissal of Nigeria's Sani Kaita after 33 minutes.
Nigeria, who like Greece had lost their opening match in South Africa, had taken an early lead after Kalu Uche's free-kick from a wide area eluded everybody.
And the Super Eagles had a firm grip on the game until Kaita foolishly kicked out at Vasileios Torosidis after both players had briefly tangled as they tried to win the ball.
Greece coach Otto Rehhagel, who presided over his team's stunning victory at Euro 2004, quickly grasped the opportunity by adopting a more attacking formation and was rewarded with a crucial victory.
A deflected strike from Dimitrios Salpingidis drew his side level before Torosidis struck the winner after the break to severely dent Nigeria's hopes of progressing beyond the group stage.
The Super Eagles, who are managed by Swede Lars Lagerback, are pointless and play South Korea, who defeated Greece, in their final match.
Greece, who now have three points, take on an Argentina side that are on the brink of qualifying after winning their first two matches.
Rehhagel's team lined up with three central defenders, two full-backs and two deep sitting midfielders - and until the dismissal of Kaita after 34 minutes it seemed that their only attacking ploy was to try to win a set-piece in a dangerous area.
Skipper Georgios Karagounis delivered cross after cross after free-kick into the Nigeria area, with recalled defender Sotirios Kyrgiakos a frequent target.
It was stale, unimaginative and one-dimensional, while Nigeria showed glimpses of precise attacking play and deservedly took the lead.
Greece keeper Alexander Tzorvas clearly thought the unmarked Peter Odemwingie would make contact with Uche's cross but the Lokomotiv Moscow striker missed the ball, which continued on its trajectory before nestling in the far corner of the net.
There was little sign of a Greece comeback until the dismissal of Kaita, who appeared to be in tears as he made his way off the pitch.
Within minutes Rehhagel had replaced the defensive Sokratis Papastathopoulos with Celtic forward Georgios Samaras.
Greece were instantly transformed - and soon cut open a stunned Nigeria defence, with a deft lay-off from Konstantinos Katsouranis playing Salpingidis through only for Vincent Enyeama to block the striker's shot.
Lukman Haruna cleared an effort from Samaras off the line but, on the stroke of half-time, Greece scored their first ever goal at a World Cup through Salpingidis's deflected strike.
Lagerback tried to bolster his side by replacing Odemwingie with Chinedu Ogbuke Obasi at the start of the second half and playing two banks of four, with Yakubu as the lone striker.
But Greece continued to threaten, with an unmarked Karagounis wastefully heading wide and Kyrgiankos forcing a save from Enyeama.
Greece really should have scored through Theofanis Gekas after an awful header from Joseph Yobo gifted him a gilt-edged opening - but his shot was saved and Nigeria broke with devastating effect.
Ogbuke Obasi slipped the ball to Yakubu, who drew a brilliant one-handed save from Tzorvas. The rebound fell to Ogbuke Obasi, who contrived to miss a sensational opportunity to restore his team's lead.
It was a pulsating passage of play that was greatly appreciated by a far-from-full Free State Stadium - but it was hardly a fair reflection of how the match had developed.
Greece were in the ascendancy and although Enyeama palmed clear a header from Torosidis he was partially at fault for Greece's winner.
The keeper could not hold a low strike from Alexandros Tziolis, with Torosidis pouncing on the rebound to spark huge scenes of jubilation.
Enyeama made two decent saves in the remainder of the game, denying Karagounis and Tziolis, but Greece held on to end a sequence of four successive defeats at the World Cup.
Attempts on target
Attempts off target
Projected table based on current scores
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