NEW YORK (AP) Nick Monroe went tumbling over the wall and suddenly realized it was a long way down, the world moving in slow motion as he fell head first toward the concrete floor.
The American doubles player was crumpled on the ground for more than five minutes during Sunday's U.S. Open match, too dizzy to stand up. He was eventually able to walk back on court under his own power, and after passing a concussion test, he returned to finish out the last three games.
In the third set of his match with Donald Young on the new Grandstand, Monroe chased after a volley hit at a sharp angle and slid into a knee-high barrier along the side of the court. He flipped over the wall, and on the other side, the base of the stands is lower than the court.
''Just saw the ball and ran for it,'' he said, ''and didn't realize the wall was there.''
Monroe added he was fairly certain he never lost consciousness and was aware of the score and the situation the whole time. Young climbed over the barrier to check on him and Monroe could hear what he was saying, but he was too dizzy to move for a couple of minutes.
Their opponents, Spain's Pablo Carreno Busta and Guillermo Garcia-Lopez, also came over to see if he was OK as medical staff attended to Monroe. He was then taken inside for close to 10 minutes for concussion tests as Young sat in his changeover chair and the Spaniards hit the ball back and forth to each other on court to stay warm.
The 34-year-old Monroe said he was put through a series of balance tests and asked to recite the months and the days of the week backward, and he passed everything.
The teams had split the first two sets and the Americans trailed 4-2 in the third when the incident happened. Monroe held in his next service game, but the Spaniards closed out the 4-6, 7-6 (4), 6-3 victory to reach the quarterfinals.
Monroe said about an hour after the match that he was still a bit dizzy and medical staff wanted him to come back to the tennis center over the next few days to continue to check on him. He's never had a concussion before.
''I guess in tennis you don't really hit your head anywhere,'' he said with a chuckle.
Monroe called the accident ''just a freak thing.''
''You're just so in the moment,'' he said. ''You want to win that bad, and you see the ball and you just go get it.''