In-form striker Graham Massey scored an 88th-minute leveller and set up Sandro Semedo's stoppage-time winner as Leyton Orient won 3-2 at second-placed Plymouth Argyle in League Two.Antoni Sarcevic fired Argyle into a 10th-minute lead from close range after target man Ryan Taylor nodded down left-back Gary Sawyer's deep far-post cross.Argyle suffered a 15th-minute injury blow when central defender Sonny Bradley hobbled off.Sarcevic later hobbled off with an ankle injury - on 37 minutes - and within six minutes Orient levelled.Left wing Massey took tally to three goals in three games with a superb solo effort, cutting in from the left before letting fly with a low 18-yard shot into the far corner.In first-half stoppage-time David Fox sent an 18-yard dipping volley - from the angle of the box - just past the upright.On-loan Cardiff City winger Matty Kennedy restored Argyle's lead on 53 minutes, smashing home from outside the box for his second goal in two home games.On the hour Kennedy curled another 18 yarder off the outside of the post with Os teenage keeper Sam Sargeant beaten.