the Mexican shrugged off a rough challenge by Andre Coelho to feed Nani but the winger's powerful first-time shot was parried away by Beto.
With a quarter of an hour left, Sir Alex's side edged in front with a goal of genuine quality. Tom Cleverley channelled David Beckham on the right wing, taking a touch to bend in a cross that invited the finishing touch. Hernandez duly obliged with a stunning header that had the net bulging in front of the Stretford End again.
The No14's work was done for the night as he left the field to a huge ovation with Ryan Giggs taking his place for the final 10 minutes or so. Braga showed they were not to be written off as De Gea's short pass to Cleverley caused some panic in defence but the Spaniard clutched a header confidently from the corner.
Van Persie should have wrapped it up when played onside to receive Nani's clever pass but the ex-Arsenal attacker was, for once, unsure with his finish and blazed over the top when a fourth goal seemed on the cards. With Ze Luis lashing a late effort off target, it did not matter too much in the final reckoning as United pull clear at the top of Group H, and are well on course to erase memories of last year's early exit from the competition.