user: Question: What is the lowest round that has Kazushi Sakuraba as the opponent?
Columns: ['Res.', 'Record', 'Opponent', 'Method', 'Round', 'Time', 'Location']
Types: ['text', 'text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Loss', '4–11–1', 'Ryuta Sakurai', 'TKO (punches)', 2.0, '3:04', 'Tokyo , Japan']
SQL:

assistant: SELECT MIN("Round") FROM "Table" WHERE "Opponent" = 'Kazushi Sakuraba';