Hello and welcome to LIVE updates of the 2018 men's US Open semi final between defending champion & world No1, Rafael Nadal and No.3 seed Juan Martin del Potro.

More from Rafa.

Nadal has wasted little time in going to speak to the Press.

The reigning champion bows out, which is a real shame as it was looking like we were in for a treat at the end of the first set.

NADAL RETIRES INJURED.

DEL POTRO IS INTO THE US OPEN FINAL!

SET! - NADAL 6-7 2-6 DEL POTRO. Nadal moves 30-0 up but is reeled in by Delpo as the errors leak off the Spaniard's racket. A long forehand offers up set point, but Nadal continues to battle and somehow fends it off. The world No.1 then slaps a backhand into the net and Delpo makes the second opportunity count with a simple crosscourt winner. It's no surprise it's two-sets to love.

NADAL 6-7 2-5 DEL POTRO. Strong focus from Juan Martin. He could easily get distracted by Nadal's issues, but he keeps hitting hard and moving the Spaniard around. He easily holds to love and is a game away from a two-set lead. You sense it won't go beyond that unless Nadal's knee problem suddenly improves - which won't happen if history is anything to go by.

NADAL 6-7 2-4 DEL POTRO. Nadal battles hard, argues with the umpire as he falls break point down before saving it. He edges in front from deuce but his movement is hampered and Delpo earns another BP with a sizzling winner down the line. Nadal lands a third ace of the match and eventually manages to stay just the one break behind.

It's looking ominous though.

NADAL 6-7 1-4 DEL POTRO. Delpo almost gives Nadal a major lift, but finds his big serve at just the right time before taking advantage of the Spaniard's troubled movement to roar back and back up the break from 0-30 down courtesy of a crisp backhand winner. Delpo playing well, but the big question is whether Nadal be able to finish this match? He looks way out of sorts now.

BREAK! - NADAL 6-7 1-3 DEL POTRO. Nadal is in big trouble. He fizzes a forehand long and then gets nowhere near a backhand pass down the line. Delpo has three bites of the cherry for the break and gets it done on the last one as the world No.1 flashes an inside-out forehand long.

Nadal clearly grimacing as his knee is massaged and strapped. It's not looking good for the Spaniard as the trainer works quickly on him during the medical time-out.

Nadal is having his right knee taped again.

NADAL 6-7 1-2 DEL POTRO. Delpo nails his first ace of the match down the middle T to cruise through a love hold.