Rafael Nadal called it one of the more scary moments he's had on the tennis court, AZERTAC reports. The world No. 1 was en route to a straight-sets win against Argentina's Federico Delbonis, leading 4-1 in the third set of their second-round match Thursday. But on a return of serve, a scorching forehand from Nadal hit a ball girl on the head. There was an audible gasp from the crowd. Nadal grimaced. "For her, probably it was not a good moment," the Spaniard said on court after the match. "I was so scared for her, honestly." The girl gave him a thumbs up, but a still-concerned Nadal and Delbonis both went over to her to make sure that she was OK. Nadal lifted the girl's hat, gave her a kiss on the cheek and patted her on the head, drawing cheers from the crowd. Nadal went on to win the match 6-3 7-6 (4) 6-1. He next will face fellow Spaniard and No. 27 seed Pablo Carreno Busta. After the win, Nadal went up to the ball girl again and handed her his headband. "She's a super brave girl," Nadal said. The Australian Open is the only major Nadal has won just once, back in 2009.