Andreas Weimann struck either side of half time to hand Paul Lambert's team a shock two-goal advantage but Hernandez was introduced at the break to score a brace himself and force the equaliser off Ron Vlaar. Robin van Persie twice hit the bar in a matter of seconds, leaving it to Chicharito to earn the plaudits by heading in the ex-Arsenal star's late free-kick.
Chris Smalling started his second successive match after returning from injury due to Jonny Evans' absence and Paul Scholes was asked to dictate the play in midfield. Yet the Reds appeared laboured from the outset in low-key first period, only enlivened by Weimann's strike at the end of the half.
Although Michael Carrick had a header from a van Persie corner comfortably clutched by Brad Guzan early on, the American keeper was not required to make another save until easily handling Wayne Rooney's ambitious long-range shot in the 44th minute.
Ashley Young, jeered on his old stamping ground, collected a Scholes pass to bend a shot wide but he had to make an important block at the other end when Christian Benteke shaped for a volley inside the box. Villa enjoyed some dangerous moments with Weimann wasting a three-on-two break and Rio Ferdinand having to clear when Benteke sprung the offside trap.
With Patrice Evra and Smalling needing treatment at various stages, it was a rough ride in defence and Gabriel Agbonlahor did not make the most of a Stephen Ireland pass, even if Smalling did miskick a poorly-placed cross. Referee Kevin Friend whistled when Ireland robbed Scholes to set up Benteke, one of a string of fouls on the midfield veteran, but it failed to provide