Although it cannot be said to be completely impossible, based on Zhou Tian's ability, if he were truly determined to blockade completely, theoretically speaking, that true god would indeed have little chance of defeating the heavenly god under Zhou Tian. Given the situation at that time, his diligence did not go unrewarded, yet achieving his original objective was nearly impossible.
In light of the situation at that time, when events unfolded as they did, that true god, after calming down, also realized that no matter how angry he was, if he couldn't trap Zhou Tian, killing the heavenly god under Zhou Tian was basically an unachievable task.