Cibulkova trailed 5 - 4 in the second set and serving to stay alive .
Cibulkova staved off three match points before holding and then breaking Radwanska en route to winning the set in a tiebreak .
Trailing 5 - 4 in the second set and serving to stay alive , Cibulkova staved off three match points before holding and then breaking Radwanska en route to winning the set in a tiebreak .