Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_87 (wins INTEGER, tournament VARCHAR, top_5 VARCHAR)

### Question ###
What is the average number of Wins in a PGA Championship with a Top-5 less than 2?

### Accurate SQL ###

SELECT AVG(wins) FROM table_name_87 WHERE tournament = "pga championship" AND top_5 < 2