Sir Alex Ferguson claimed a controversial incident involving referee Chris Foy cost Manchester United victory in the Community Shield.
United lost the traditional curtain-raiser to the new season 4-1 to Chelsea in a penalty shootout after the Premier League and FA Cup winners ended 90 minutes of end-to-end action level at 2-2.
Nani had fired United into an early lead before Ricardo Carvalho restored parity soon after half-time.
Frank Lampard edged Chelsea ahead in the 71st minute but Ferguson was unhappy with the build-up to the goal.
Referee Foy allowed play to continue when Michael Ballack appeared to body-check Patrice Evra just minutes after pulling up Evra when Ballack was injured on the turf despite no foul being committed.
Wayne Rooney netted a stoppage-time equaliser for the Red Devils, but Ferguson was far from happy with the passage of play which led to his side falling behind.
"That incident cost us the game," he said. "I thought the referee saw it - he (Ballack) elbowed him (Evra) in the face and he (Foy) was clearly in line with the actual incident.
"I'm disappointed because he (Foy) stopped the game twice before that for fouls, or for players lying down.
"Ballack was lying down and he got up within seconds but he (Foy) thought it was serious - a serious foul.
"We've got to a level now where it's being used as a professional way of getting a game stopped."