Blake claimed his second Champions Tour win of the year. He had waited nearly 20 years for a title before winning in Korea earlier this season.
Lehman, meanwhile, claimed the year-long Charles Schwab Cup title and its $1 million annuity after holding off Calcavecchia in a close battle.
Calcavecchia needed to finish tied for second with only one other player Sunday, but he shared the spot with Roberts, Allen and Haas.
Calcavecchia also needed Lehman to come in no better than a two-way tie for 12th. Lehman finished tied for 18th Sunday after shooting a 1-over 72.