The Liverpool captain had given the hosts the lead after 68 minutes when he curled a free-kick through the United wall and into the net.
But the Mexico striker’s instinctive header in the 80th minute earned a valuable point for the visitors as they battled back to snatch a draw on Merseyside.
The result leaves Sir Alex Ferguson’s defending champions top of the Premier League table, with Liverpool in fifth, six points behind the leaders.
After what was a cagey opening to the game, Phil Jones had Liverpool goalkeeper Pepe Reina scrambling at his near post when he headed Patrice Evra’s deep cross into the side-netting.
The home side then carved their own first real opportunity when Gerrard whipped a delightful ball across the face of goal – but Luis SuÃ¡rez was unable to make contact.
And moments later the Uruguayan, clearly oozing with confidence following his flying start to the season, chested the ball down and volleyed an audacious shot from just inside the United half which dropped wide.
SuÃ¡rez then spurned a glorious opportunity to put Liverpool ahead in the 34th minute when he jinked past United’s defence, only to see his low left-footed effort well saved by David De Gea.
The Reds started the second half brightly – and Dirk Kuyt had his shout for a penalty turned down by referee Andre Marriner five minutes after the break when the Dutchman’s header appeared to strike the arm of Jonny Evans in the box.
But Kenny Dalglish’s men were able to make their second-half dominance count moments later through Gerrard after Rio Ferdinand clumsily brought down Charlie Adam as the Scot burst towards goal.
The Liverpool skipper stepped up to take the resulting free-kick on the right of the box, and as Ryan Giggs bizarrely peeled off the end of the United wall, Gerrard slotted his shot through the gap past a despairing De Gea.
United boss Ferguson had no choice but to throw Wayne Rooney, Nani and HernÃ¡ndez into the mix – and it was the Mexico striker who hauled United back level with 10 minutes to play.
Nani’s driven corner was flicked on by Danny Welbeck and HernÃ¡ndez nodded home with a typically clinical header.
Liverpool could have taken the lead again just seconds later when Kuyt forced a brilliant save from De Gea after being found by Stewart Downing’s searching cross.
And substitute Jordan Henderson then forced another astute stop from the United goalkeeper with a dipping volley, before sending a free header flying over the bar moments later.
In the end, it was probably a fair result as Liverpool were forced to settle for a hard-earned point and Manchester United extended their unbeaten start to the season.
Liverpool: JosÃ© Reina, JosÃ© Enrique, Martin Kelly, Jamie Carragher, Martin Skrtel, Lucas Leiva (Jordan Henderson, 57), Dirk Kuyt, Steven Gerrard, Charlie Adam, Stewart Downing, Luis SuÃ¡rez.
Manchester United: David De Gea, Phil Jones (Javier HernÃ¡ndez, 76), Chris Smalling, Rio Ferdinand, Jonny Evans, Patrice Evra, Ryan Giggs, Park Ji-Sung (Wayne Rooney, 69), Ashley Young (Nani, 69), Darren Fletcher, Danny Welbeck.
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