On a scorecard for a standard first-to-seven tiebreak, 7-6 (4) means the set went to a tiebreak and the loser took four points in it. The winner won the breaker 7-4. The set itself still finished only one game apart.
At 7-6 the winner finished one game ahead. A set score of 7-5 would cover -1.5, even though both sets end with seven games for the winner.
It decides that set. Check how many sets the player already won and the scheduled format for that fixture before reading the match result.