Good evening, and welcome to our LIVE coverage of Juan Martin del Potro v Steve Johnson. The players are on court and just about ready to go.

That's the end of our live text commentary for tonight. Thanks so much for your company! Join us again tomorrow for more US Open action.

Del Potro signs some tennis balls and hits them into the crowd, who hail him appropriately. Great display from him - would it be tempting fate to begin to wonder whether he's truly back to full fitness now?

"Thank you for inviting me, and giving me the wild card!" he says.

Del Potro thinks he played well, and thanks the crowd for helping him get through.

Ironic, seeing as Johnson was the one who was worried about the wildcard knocking out an American player, and now he's the American knocked out.

Johnson 6-7 3-6 2-6 Del Potro: Johnson tries the chip and chase tactic, and has some success, but it's all a little too late. He still tries a weak backhand against the massive Delpo forehand, and the Argentine is dominant.

Johnson 6-7 3-6 2-5 Del Potro: Del Potro doesn't just have power in the locker, he also has delicacy when he wants it, and he puts it on court here, dinking the ball over the net to break Johnson again.

Johnson 6-7 3-6 2-4 Del Potro: Johnson's now getting some lift on his forehand as well which rattles Del Potro. The Argentine, however, is not going to be broken that easily.

Johnson 6-7 3-6 2-3 Del Potro: Johnson's moving his feet - clad in bright blue shoes - much quicker and is deft in his movement, trying to combat the Delpo power that way.

Johnson 6-7 3-6 1-3 Del Potro: Johnson is livid with himself after losing the advantage with a limp low backhand into the net.

Johnson 6-7 3-6 1-2 Del Potro: There are some loud shouts from the crowd in an attempt to boost the American, who's lost his way now but at least manages to hold his serve.

Johnson 6-7 3-6 0-2 Del Potro: Comfortable for Del Potro now, who's making magnificence look routine.

Johnson 6-7 3-6 0-1 Del Potro: Looking good for Delpo now, third straight break for him and Johnson isn't managing to hurt him in return.

Johnson 6-7 3-6 Del Potro: A comfortable hold to love for Juan Martin del Potro, and that is the second set. After Johnson went up by that early break, one wouldn't have predicted that coast.

Johnson 6-7 3-5 Del Potro: The Del Potro forehand is so terrifyingly competent. He tears across court and Johnson has nothing in response as the second set begins to roll away from him.

Johnson 6-7 3-4 Del Potro: Del Potro holds now, and edges in front in this second set.

Johnson 6-7 3-3 Del Potro: Lovely from Del Potro, who's stepping it up against the seeded American. Johnson tries a clever flick around his own back, but that's not enough, although it draws applause.