This study examines the impact of flipped classroom teaching on postgraduate tennis courses in Chinese universities, focusing on student perceptions, learning outcomes, and instructional effectiveness. The flipped classroom model, which reverses conventional instruction by delivering theoretical content outside the classroom and dedicating in-class time to active learning, has gained traction as a student-centered pedagogical approach. However, its application in physical education (PE) and skill-based contexts remains underexplored. Using a mixed-methods design, this study evaluated knowledge acquisition, skill development, and student engagement in flipped versus traditional classrooms. Data collected from pre- and post-assessments, surveys, and semi-structured interviews revealed that students in the flipped group improved their knowledge scores from 65% to 85% and skill scores from 60% to 88%, compared to the traditional group’s gains from 64% to 75% in knowledge and 59% to 74% in skill. Paired sample t-tests confirmed that these improvements were statistically significant, with a t-value of 5.63 (p = 0.000) for the flipped group and 3.12 (p = 0.002) for the traditional group. Survey analysis showed that 78% of students reported enhanced engagement, 76% noted better comprehension, and 76% found it easier to apply techniques using the flipped method. A correlation analysis further indicated a strong positive relationship between engagement and comprehension. These findings highlight the flipped classroom’s effectiveness in improving both theoretical understanding and practical performance in sports education, offering valuable implications for instructional design in university-level PE programs.