The Mexican international connected for a looping header in the opening minutes to score in his third consecutive FA Cup match, but the Red Devils blew a two-goal edge.
Chelsea battled back from a two-goal deficit, and the two sides will be forced to replay the fixture at Stamford Bridge to determine which of the two advances to the competition semifinals at Wembley Stadium. They followed suit after Blackburn and Millwall played to a scoreless draw earlier in the day and set up a replay of their own. Manchester City and Wigan Athletic booked their places at Wembley by taking care of business on Saturday.
Starting up top alongside Wayne Rooney, who returned to the lineup following his controversial UEFA Champions League omission in Tuesday's loss to Real Madrid, Chicharito got to work immediately. Michael Carrick picked him out with an expert chip, and the Mexican forward connected for a looping header to the far post with Gary Cahill still tracking back and goalkeeper Petr Cech rooted to the ground. His ball tucked under the crossbar to set the tone for a celebratory affair.
Rooney followed up with a goal of his own six minutes later to assert United's dominance, but the Red Devils succumbed to goals from Eden Hazard and Ramires to settle for the draw. Chicharito nearly had his second midway through the first half, making a near-post run to meet Shinji Kagawa's cross, only to put his effort wide of the post. He was subbed off for Robin van Persie in the 63rd minute.
The goal was Chicharito's 16th of the season in all competitions and fourth in the FA Cup. He has scored in all of them against Premier League opposition (Fulham, Reading, Chelsea).