The expansion team announced Wednesday that ticket sales have passed the 50,000 mark for the game against the Chicago Fire on Saturday afternoon at Olympic Stadium.
The Impact are hoping to beat the local attendance record for a soccer match of 58,542 set for a playoff game by the defunct Montreal Manic against the Chicago Sting in 1981.
About 2,000 seats were added in temporary grandstands at field level this week to boost capacity to more than 58,500.
''We have to believe that we can beat the Manic’s record,'' executive vice-president Richard Legendre said in a statement.
The Impact joined MLS as its 19th franchise this season. The team lost 2-0 to the Whitecaps in Vancouver in its regular-season debut.