Bryce Harper was so overwhelmed by winning the second MVP award of his career on Thursday ... he broke down in tears.
MLB Network cameras captured the emotional moment ... just seconds after the league announced the Philadelphia Phillies star was the recipient of the honor.
Harper -- who was wiping tears off his cheeks throughout his interview with the network -- said this one meant a significant amount to him, considering he had started the year in April by being drilled in the face with a 97 MPH fastball.