Manchester United needed a late equaliser to keep the last 16 tie against Atletico Madrid in the balance after a 1-1 draw in the first leg at Wanda Metropolitano.
Man United recalled Marcus Rashford, who formed a front three with Jadon Sancho and Bruno Fernandes, just behind lone-striker Cristiano Ronaldo, while Atletico brought back Angel Correa to partner Joao Felix upfront, instead of Luis Suarez, who dropped to the bench.
The hosts had a bright start as Felix gave them the lead in the seventh minute with a diving header that went in off the post after a cross by Renan Lodi.
The Red Devils were struggling to sustain their attacking moments and they were fortunate not to 2-0 down on the stroke of half-time after Marcos Llorente's header at the back post came off the crossbar from another delivery by Lodi.
Ralf Rangnick's troops were absorbing the pressure in the early stages of the second stanza and eventually equalised ten minutes before time from a counter-attack after Anthony Elanga finished a one-on-one chance from Fernandes' through ball.
Antoine Griezmann came close to snatching the winner for Diego Simeone's men in the dying minutes with a curling strike that crashed the crossbar.
Benfica twice came from behind to keep the last 16 contest against Ajax Amsterdam still square after a four-goal thriller in the first-leg at Estadio da Luz.
Ajax lined up in their traditional 4-3-3, as Anthony and Dusan Tadic flanked former West Ham United forward Sebastien Haller while Cameroonian goalkeeper Andre Onana settled for a place on the bench.
Erik ten Hag's charges were on the front foot in the opening exchanges and Tadic eventually gave them the lead in the 18th minute with a side-footed finish towards the far corner after a cross by Noussair Mazraoui.
Benfica were fired up after that and found the equaliserin the 25th minute thanks to an own goal by Haller, who deflected former Tottenham Hotspur defender Jan Vertonghen's cross from a corner unintentionally past goalkeeper Remko Pasveer.
However, Ajax had a quick response as Heller redeemed himself four minutes later and restored their lead with a close-range finish at the near post after shot-stopper Odysseas Vlachodimos spilled a cross into his feet.
Ten Hag's men were all over Benfica coming from the half-time break but they were caught on counter-attack, as Roman Yaremchuk levelled matters for the Portuguese side 18 minutes before time with a header into an open net after Pasveer parried Goncalo Ramos' cracking strike onto his path.
