As a result of the COVID-19 virus outbreak, there has been a dramatic change in the educational landscape, and traditional classroom instruction has shifted to the online environment. Previous research has yielded contradictory results regarding the effect of different instructional modalities on student achievement. This study aimed to examine the impact of teaching mode (online vs. face-to-face) on academic outcomes in the context of Spanish as a foreign language in China. A comparative analysis was conducted between two cohorts of students, one receiving online courses and the other undergoing in-person instruction, and their respective scores for Spanish tests are reported. Additionally, a questionnaire was administered to the online cohort to gain insight into their learning motivation. The results showed that students who received online instruction outperformed those who received face-to-face instruction. Regarding the potential factors underlying the superior academic outcomes of online learners, examination of questionnaire responses pertaining to their learning experience reveals that students' motivation, learning strategies, self-regulation, and self-efficacy are crucial factors of successful learning results and may have positively contributed to such outcomes.