user: Question: Who was the opponent during the UFC 90 event with a fight that lasted less than 4 rounds?
Columns: ['Res.', 'Record', 'Opponent', 'Method', 'Event', 'Round', 'Time', 'Location']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Loss', '11–2–1 (1)', 'TJ Grant', 'KO (punches)', 'UFC 160', 1.0, '2:07', 'Las Vegas, Nevada , United States']
SQL:

assistant: SELECT "Opponent" FROM "Table" WHERE "Round" < 4.0 AND "Event" = 'UFC 90';