"To complete the comeback" means to successfully recover from a difficult situation or make a successful comeback after facing obstacles or setbacks. Full definition
The forward has demonstrated his class on occasion — when fitness has permitted — and will be desperate to complete his comeback with a strong showing in the final. (caughtoffside.com)
However, they just ran out of time and couldn't complete the comeback.. (allsportsseries.com)
Manuel Pellegrini's side clinched Group D spot after completing another comeback to secure the victory at Etihad. (footballtarget.com)