A relatively emerging subject called blended learning mixes conventional classroom methods with online instruction. Recent studies that look at the academic and social benefits of this teaching method have emphasised the usage of blended learning. Since it combines traditional and online teaching modes, the strengths of blended learning rest on both teaching approaches. However, literature on the difficulties that English language instructors' experience while implementing blended learning is still scarce. A process of in-depth critical analysis of existing literatures on blended learning is carried out. Hence, this paper presents the benefits and challenges of blended learning on tertiary education ESL classrooms along with the comparison of UTAUT 2 model.