Classy United put 8 past Gunners Manchester United 8 (Wellbeck 22, Young 28, 90, Rooney 41, 64pen, 82, Nani 67, Park Ji-Sung 70) Arsenal 2 (Walcott 45, van Persie 74)

Rooney shows Young the art to the perfect penalty during Uniteds 8-2 mauling of Arsenal today at Old Trafford

Manchester United inflicted total humiliation on Arsenal and their embattled manager Arsene Wenger with a brutal victory at Old Trafford.

Sir Alex Ferguson's Premier League champions responded in spectacular fashion to Manchester City's outstanding 5-1 win at Spurs by returning to the top of the table with a result that represented Arsenal's worst defeat since 1896.

Wenger sent out a makeshift side depleted by injuries and suspensions - but even this cannot excuse the manner in which they were outclassed in all parts of the pitch and swept aside with such ease by United.

Wayne Rooney was United's inspiration with the sixth hat-trick of his Old Trafford career, but Ashley Young also made his mark with two stunning goals. Danny Welbeck, Nani and Park Ji-sung were the other scorers.

Theo Walcott reduced United's three-goal advantage on the stroke of half-time but Robin van Persie's strike late in the second half-represented no measure of consolation for a dispirited, broken Arsenal.

United keeper David de Gea distinguished himself with a fine penalty save from Van Persie moments after Welbeck had opened the scoring - and in a game of almost unrelenting misery for Arsenal, teenager Carl Jenkinson ensured they have failed to end a game with 11 players in any of their league games this season when he was sent off.

Old Trafford was understandably exultant at the conclusion of such a carnival performance but Wenger now faces defining days of his Arsenal reign before the transfer window closes on Wednesday.

This result underscores the gulf that has opened up between United and Arsenal and Wenger will now seek to address the weaknesses in his squad and replace the departed Cesc Fabregas and Samir Nasri.

Ferguson's faith in the team that won so convincingly against Tottenham was rewarded with another thrilling attack-minded performance.

Arsenal's uncertainty was partly explained by the unfamiliar make-up of their team, but the flaws were swiftly exposed by the manner in which United took the lead. Anderson's lofted pass was inventive but Arsenal's failure to react was ominous for what lay ahead, allowing Welbeck to head past Wojciech Szczesny.

Van Persie then squandered an instant opportunity to equalise after referee Howard Webb awarded a penalty when Walcott tangled with Jonny Evans in the area. De Gea has had a mixed start to his Old Trafford career but he was engulfed by his team-mates as he dived to his right to make a fine save.

And United ensured Arsenal were punished heavily as Young added the second after 28 minutes. Young found space just outside the area and curled a perfect finish high beyond Szczesny's grasp at the Stretford End.

Welbeck's game was cut short by a hamstring injury - but there was no respite for Arsenal as Rooney worked a free-kick routine with Young to send a 20-yard free-kick into the top corner as the interval approached.

Walcott halted some of United's momentum when he took advantage of slack marking to shoot beneath De Gea in first-half injury time.

It made little difference amid the carnage of the second half as Arsenal were torn apart amid a torrent of goals, near misses and saves from the desperately exposed Szczesny.

Arsenal survived until the 64th minute when they were undone by another piece of Rooney creation at a set-piece, again linking with Young before dispatching the finish past the motionless Arsenal keeper.

It was the breaking point for Arsenal and they spent the remainder of game in a constant state of siege. Rooney was the creator for Nani with the pass that gave the Portuguese the opportunity to send a flamboyant chipped finish over Szczesny for United's fifth.

With the Gunners in disarray, Park marked his arrival as substitute by lashing home an unstoppable finish before Van Persie briefly interrupted the one-way flow towards Arsenal's goal by beating De Gea.

It barely seemed possible for matters to get worse for Arsenal, but the agony increased when Jenkinson was sent off after receiving his second yellow card for fouling Javier Hernandez as he raced clear.

Rooney completed his thrilling treble with a penalty eight minutes from time after Walcott fouled Patrice Evra.

And United completed the scoring with their eighth in injury time, Young once again showing his eye for the spectacular with another curling shot.

Wenger cut a despairing figure as he walked back to the dressing room at the final whistle after one of the darkest days of his career.

Manchester United: 01-De Gea, 03-Evra, 04-Jones, 06-Evans, 08-Anderson, 10-Rooney, 12-Smalling, 17-Nani, 18-Young, 19-Welbeck, 23-Cleverley SUBS USED: 11-Giggs, 13-Park Ji-Sung, 14-Hernandez

Arsenal: 13-Szczesny, 06-Koscielny, 07-Rosicky, 10-van Persie, 14-Walcott, 16-Ramsey, 20-Djourou, 23-Arshavin, 25-Jenkinson, 30-Traore, 39-Coquelin SUBS USED: 15-Oxlade-Chamberlain, 29-Chamakh, 46-Lansbury

South Korea 2 Greece 0

Scorers: Lee (South Korea), Park (South Korea)

Attendance: 31,500

Korea Republic claimed the first victory at the 2010 FIFA World Cup South Africa™ as a goal early in each half made it a disappointing start for Group B opponents Greece.

The South Koreans were the dominant force for virtually all of the first half in the Port Elizabeth Stadium although they had to withstand some initial pressure from Greece with Vasileios Torosidis seeing an effort fly off target. The same player should then have scored following Georgios Karagounis's corner but he put a decent chance wide from nine yards.

Huh Jung-Moo's side shrugged off that scare and proceeded to pin their opponents back, and with only seven minutes gone they forged ahead. A free-kick from near the left-hand corner flag found the blue shirts all at sea and at the far post Lee Jung-Soo pounced to sidefoot home and become his country's fastest-ever scorer at a FIFA World Cup.

Greece, European champions in 2004, never recovered from that setback and Korea smelled the chance of further goals with Manchester United's Park Ji-Sung always a danger and Yeom Ki-Hun also pulling the strings. In the 28th minute the South Koreans, fast-raiding and adroit with their ball control, fashioned an outstanding chance to double their advantage as Park Ji-Sung slid a lovely ball into the feet of Park Chu-Young.

Park Chu-Young was clear of the last man but just as he attempted to seal his strong run with a scoring finish, a combination of the back-pedalling Loukas Vyntra and Alexandros Tzorvas denied him, the goalkeeper making a vital intervention to deflect the ball over. Greece had to change their approach and Otto Rehhagel decided to take off captain Karagounis at the break with Christos Patsatzoglou coming in. However with another goal seven minutes into the second period, Korea put the game as good as out of reach.

It was a disaster for Greek defending as they gave possession away inside their own half through Vyntra and were left helpless as Park Ji-Sung took ruthless advantage. There was strength, control and determination in his run as he tore into the penalty area before burying a left-footed shot past Tzorvas to become only the second Asian player to score in three different FIFA World Cups, having also found the net in 2002 and 2006.  It should have been three minutes later as Park Chu-Young dashed between defenders to meet a cross from the right but he could not keep his header down.

Greece, who had not managed a goal in any of their three previous FIFA World Cup games – all of which had been lost in 1994 – had no option but to give everything to try and claw back the deficit. They looked to Theofanis Gekas, who with ten goals was the leading scorer in European qualifying, to inspire an recovery, and he tried an ambitious overhead kick which went over. Soon after Pantelis Kapetanos scooped the ball over as it was drilled in from the left while Gekas forced Jung Sung-Ryong into a fine save at the end. But there was no dispute that Korea were good value for their three points.

South Korea: 18. Jung, 4. Cho, 07. Park, 8. Kim, 10. Park, 12. Lee, 14. Lee, 16. Ki, 17. Lee, 19 Yeom, 22. Cha

Subs Used: 05. Kim, 11. Lee, 15. Kim

Greece: 12. Tzorvas, 2. Seitaridis, 6. Tziolis, 7. Samaras, 8. Papadopoulos, 9. Charisteas, 10. Karagounis, 11. Vyntra, 15. Torosidis, 17. Gekas, 21. Katsouranis

Subs Used: 3. Patsatzoglou, 14. Salpigidis, 20. Kapetanos