user: ### NOW ANSWER:
Question: Location of Boston Garden, and a Record of 58-23 involved what opponent?
Columns: ['Game', 'Date', 'Opponent', 'Score', 'Location', 'Record']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [74.0, 'Wed. Apr. 1', 'Washington Bullets', '103-86', 'Boston Garden', '54-20']
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Location" = 'Boston Garden' AND "Record" = '58-23';