* Benfica's Cardozo scores twice in last 10 minutes * Sporting suffer fourth league defeat this season * Ninth-placed club endure worst ever league start (Adds quotes) LISBON, Dec 10 (Reuters) - Benfica scored three second-half goals to earn a thrilling 3-1 comeback win over struggling Sporting on Monday to stay top of the Portuguese Premier League while their Lisbon rivals endure their worst league start in nearly 80 years. ... More...