Robin van Persie salvaged Manchester United's UEFA Champions League dream as his hat-trick beat Olympiacos 3-0 and booked a last-eight spot.
The hosts had trailed 2-0 heading into the second leg, with manager David Moyes under huge pressure to produce a result, but the Scot avoided a Greek tragedy with the help of his prolific Dutch frontman.
Penalties have become a familiar sight at Old Trafford in recent days - United conceded three in the weekend Premier League mauling by Liverpool - and Van Persie put the hosts ahead from 12 yards when one went their way in the 25th minute after a foul by Jose Holebas.
The Netherlands striker doubled his tally on the stroke of half-time to level the tie on aggregate, before curling home a free-kick seven minutes into the second period to seal the win and a famous comeback.
The result takes United into the last eight for the first time since 2011, while Olympiacos have now lost on all 12 of their visits to England, conceding an average of three goals.
Moyes made four changes from Sunday's 3-0 Premier League defeat at home to fierce rivals Liverpool, bringing Rio Ferdinand and Ryan Giggs into an experienced starting XI, and it was United who did the early pressing.
Wayne Rooney was first to challenge visiting goalkeeper Roberto, with the Spanish shot-stopper electing to extravagantly punch clear from a free-kick, but United's Herculean task almost became even greater 15 minutes in, when Hernan Perez scooped the ball over after good work by Joel Campbell to set up the opportunity.
Rooney went agonisingly close to making the visitors pay for that miss as he headed against the left-hand post from Giggs' cross, with replays suggesting that Roberto may have got the slightest of fingertips to the ball.
But United broke the deadlock from the spot after 25 minutes - Van Persie powering home after he had been recklessly bundled to the ground from behind by Holebas.
Patrice Evra had Roberto diving at full stretch 10 minutes before the break, forcing the Spaniard into an impressive stop with a headed effort from Van Persie's corner.
David De Gea then made a crucial double save at the other end, first denying David Fuster's header and then recovering well to keep out Alejandro Dominguez's effort from close range.
And United were level in the tie in first-half stoppage time when Van Persie tapped home through the legs of Roberto after a cross from Rooney.
The Dutchman was single-handedly rescuing their hopes, and he completed his treble in the 52nd minute by curling a 20-yard free-kick around the Olympiacos wall and beyond a statuesque Roberto to give the home fans belief and lift a considerable weight off Moyes' shoulders.
However, he almost had the ball in the back of his own net shortly afterwards when Dominguez's free-kick deflected narrowly wide off his head.
The delicate nature of the scoreline was emphasised when Fuster's rifled effort straight at De Gea in the 67th minute had many a Mancunian heart in their mouth, with Olympiacos still only a single away goal from victory.
But United weathered a late storm to cling on to an important victory, although the sight of Van Persie leaving the field on stretcher late on will be of some concern.
|20||R. van Persie||25' 45+1' 52'|
|Coach: D. Moyes|
for A. Valencia 77'
for D. Welbeck 82'
for R. van Persie 90+1'
|Ancelotti shocked by Lampard, Manchester City link|
|Nuno thankful for ´big influence´ of Mourinho|
|Sporting Kansas City 1 Philadelphia Union 1: Brown´s maiden goal secures Union draw|
|Blanc hails ´natural leader´ Ibrahimovic|
|Van Gaal: ´Maybe we don´t need other players´|
|Rodgers: ´One or two areas´ to strengthen|
|No Ronaldo for United clash|
|Monaco look to replace Rodriguez|
|Garcia pleased with Roma form|
|Swansea well beaten by Bournemouth|
|Pellegrini concerned by ´high risk´ pitch|
|Poyet issues Wickham warning|
|Ramos makes Dortmund bow in Chievo win|
|Medel agent in Cardiff to discuss Inter deal|
|Remy to join up QPR squad|
|Falcao to feature against Valencia|
|Wenger brushes off Balotelli rumours, Gerrard claims|
|Blanc stresses Trophee des Champions importance|
|Pardew hopeful of Ferreyra loan|
|Leeds to meet with police to discuss outstanding fees|
|Bernabeu redevelopment plans halted by Spanish court|
|Malaga complete Ochoa deal|
|Man arrested over match-fixing claim in Bulgaria|
|Osvaldo could join Inter in Taider swap|
|Murcia denied Segunda participation over financial woe|
|Guardiola delighted with Guadalajara triumph|
|Wenger rules out Quintero capture|
|Ansaldi joins Atleti on loan|
|Seferovic signs on at Frankfurt|
|Van der Vaart not ruling out QPR move|
|Hiddink eyes more Netherlands progress|
|Palace snap up free agent Hangeland|
|Davies competition can help me improve, insists Rose|
|Basanta completes Fiorentina move|
|Sporting slam Dier´s father and representative|
|Grenier denies missing training|
|Lazio bring Braafheid in from the cold|
|Leboeuf: Ibrahimovic should be PSG captain instead of Silva|
|Villa must heed Keane advice, says Lambert|
|Falque joins Genoa|
|Henderson: Gerrard is irreplaceable|
|Milner: I´ll stay if I´m playing|
|Samp swoop for Bergessio|
|Evans impressed by Van Gaal´s attention to detail|
|Cordoba sign Rossi on loan from Juve|
|Brondby ´will do everything´ to sign Agger|
|Seedorf ´still has Milan contract´|
|Blaszczykowski: Dortmund will always be number one|
|Mourinho hints at Cech exit|
|Osman sets sights on silverware|
|Sahin to miss Dortmund´s Bundesliga opener|
|Griezmann ´didn´t think twice´ about joining Atletico|
|Fletcher tips bright future for Herrera|
|Swedish defender Mellberg retires|
|Copa do Brasil Review: Vasco da Gama, Novo Hamburgo advance|
|Courteous Chelsea players welcome Courtois|
|UEFA to investigate fan violence in Kiev|
|Ribery shines as Bayern edge out Guadalajara|
|Lampard´s short-term future set to be decided|
|Villa wants to leave legacy|
|Cabaye fresh for PSG´s trophy assault|
|Pique: I am far from the world´s best defender|
|Schneiderlin staying put, says Koeman|
|Digne: PSG have acclimatised in China|
|Atletico say no to Torres, Hernandez|
|Mata buoyed by early form|
|Bruce rues calamitous Huddlestone miss|
|UEFA Europa League Review: Torino mark return with big win, Lyon victorious|
|Southampton win again|
|Jenkinson agrees West Ham loan|
|Tottenham agree Dier move|
|Rincon seals Genoa move|
|Dunne announces international retirement|
|Romulo close to Juve switch|
|Trencin 0 Hull City 0: Huddlestone pays penalty in Hull stalemate|
|Rennes prise Prcic away from Sochaux|
|CSL Preview: Liaoning look for swift response, buoyant R&F visit Henan|
|Pique desperate to regain high standards|
|Marseille agree three-year Stade Velodrome lease|
|Torres will not be leaving, says Mourinho|
|Bastia bring in Brandao|
|Paris Saint-Germain v Guingamp: League and cup winners battle for Trophee des Champions|
|Argentine Primera Division suspended after Grondona death|
|Immobile: Lewandowski is the past, I am the future|
|Rose pens new Tottenham deal|
|CSL Review: Evergrande end Harbin run, Henan edge clear of danger|
|Ivory Coast appoint Renard|
|Three-man shortlist for South Korea post|
|MLS Preview: Sounders aiming to bounce back against Earthquakes|
|Personal reasons behind Evra´s Juve switch|
|Liga MX Preview: Monterrey out to continue winning run|
|J.League Preview: Oenoki begins S-Pulse reign at Tokyo|
|K.League Preview: Jeonbuk face tricky Jeonnam test, Pohang visit Suwon|
|Kakuta loaned to Vallecano|
|Morrison remanded in custody|
|Hernandez coy on United exit|
|Neymar on road to recovery|
|Feyenoord capture Wilkshire and Basacikoglu|
|Yoel makes Valencia switch|
|Heaton extends Burnley deal|
|Lees leaves Leeds for Wednesday|
|Caballero eyes first-team action|
|Newcastle ´monitoring´ Remy, claims Pardew|
|Rodriguez ready to fight for Real place|
|Cavani ´certain´ he will stay with PSG|
|Morrison charged with assaults|
|Copenhagen slam security after fan violence in Kiev|
|Gerrard: Suarez ´too good´ for Arsenal|
|Mourinho explains Lukaku exit|
|Simeone content with Atleti workout|
|Milligan: Australia targeting Asian Cup|
|Ronaldinho rules out retirement|
|Rodgers challenges Henderson|
|Jovetic can be City catalyst - Pellegrini|
|Janko joins Sydney as marquee|
|Deila ´unbelievably disappointed´ with Celtic|
|MLS Review: DC close on Sporting, Red Bulls hold RSL|
|Ecuadorian Primera A Review: Emelec crowned champions|
|Bolivar 1 San Lorenzo 0 (agg 1-5): Visitors advance to maiden Libertadores final|
|Gerrard open to move abroad|
|Lukaku tells Chelsea ´no hard feelings´|
|Zaha eager to impress Van Gaal|
|Liverpool down Man City after shoot-out|
|Atletico fall to Gonzalez´s penalty heroics|
|Glazers offer up 8m United shares|