LONDON — Former U.S. Open champion Juan Martin del Potro says he needs to consult a doctor after injuring his left knee and ankle during a third-round victory at Wimbledon.

Del Potro overcame a scary late fall to beat Grega Zemlja of Slovenia 7-5, 7-6 (3), 6-0 Saturday, but said he twisted his ankle and hyper-extended his knee.

Del Potro hurt his left leg when chasing down a drop shot in the third set, skidding awkwardly on the grass and tumbling face first. He received treatment after taking a 4-0 lead and took a medical timeout after the next game, and returned to break Zemlja again to clinch the win.

The eighth-seeded Argentine said "it was really painful. I was a little scared at that moment. ... Now I start to feel something in my knee and my ankle, as well. I will check with the doctor very soon."