Clue: Mostly wonderful, tense batter's innings (6)
Answer: WICKET
Explanation: Definition: batter's innings
 **Last letter ****deleted from**(Mostly) "wicked"(informal term for "wonderful!"/excellent!) + T(abbrev. for "tense").
Defn: …/in cricket, the time during which a batsman/batter is at bat, and that represents his innings.