Steven Gerrard was sent off less than a minute after coming on as Manchester United beat Liverpool 2-1 on Sunday in the Premier League with two goals from Juan Mata.
The 34-year-old Gerrard was shown a straight red card for stamping on Ander Herrera after replacing Adam Lallana at the start of the second half.
Mata scored in the 14th minute at Anfield before doubling the lead with a spectacular scissor-kick in the 59th after an assist from Angel de Maria.
Daniel Sturridge got one back for Liverpool in the 69th before Wayne Rooney's penalty was saved by Liverpool goalkeeper Simon Mignolet right at the end.
Soccer great Pele was among those watching what is traditionally the biggest match in English football.
Fourth-place United strengthened their grip on a Champions League spot, moving five points clear of fifth-place Liverpool.
Goals from the outstanding Mata decided the outcome but Gerrard's indiscipline was a major contributory factor in Liverpool's first league defeat since losing 3-0 at Old Trafford in mid-December.
Referee Martin Atkinson had no choice at the inexcusable stamp from the most experienced player on the field. Gerrard leaves for the Los Angeles Galaxy in the summer and this was his last match against United.
Much had been made of the success of Liverpool manager Brendan Rodgers' 3-4-2-1 formation he first employed in that Old Trafford reverse. However, it worked against Liverpool in the first half on Sunday as United manager Louis van Gaal was the man with the right plan.
United played a high midfield four behind lone striker Rooney, pushing Mata and Ashley Young into advanced positions. Mata, in particular, used it to great effect against the relatively inexperienced Alberto Moreno.
Spanish World Cup winner Mata cleverly moved from outside to inside and back again to generate space for himself and left-back Moreno was left in a quandary whether to mark or hand over to center-back Mamadou Sakho.
Herrera spotted this weakness and in the 14th threaded a pass between the two Liverpool players for his compatriot to run onto and clip a shot past Mignolet.
It was a rare moment of quality from either side as Sturridge thrashed an ambitious left-foot volley over and Lallana wastefully drove wide from Liverpool's best move of the match that involved Raheem Sterling, almost anonymous in the first half, and Jordan Henderson switching play from right to left for Sturridge to provide the perfect lay-off.
Gerrard's emergence after the interval offered renewed optimism, but that ended almost immediately with his dismissal. He will now miss the trip to Arsenal after the international break and the FA Cup quarter-final replay at Blackburn four days later.
Phil Jones escaped with a yellow card for clattering Henderson out by the touchline with a high challenge but that was the least of Liverpool's problems as Mata finished off a clever reverse pass from substitute di Maria to acrobatically volley home.
Philippe Coutinho teed up Sturridge to score his fifth goal of an injury-disrupted season, offering late hope to the hosts. Although Liverpool made light of its numerical disadvantage, United - with Marouane Fellaini winning virtually every header at both ends of the pitch - had enough discipline to hold on.
United could even afford for Rooney to have a penalty saved by Mignolet in added time after Emre Can's foul on Daley Blind.
Liverpool defender Martin Skrtel incensed United in the closing moments of the game for what appeared to be a nasty challenge on goalkeeper David de Gea.