It takes a lot to send a lob over Juan Martin del Potro. The big friendly Argentine stands at 198cm tall, a frighteningly large presence across the net. And that's before he's begun welting his forehand like he's pelting a baseball.
With the Sydney title already on his winning sheet for 2014, the former US Open champion is one of those viewed to be a real, realistic contender for Grand Slam glory, taking some of the limelight away from the Big Four. After all, he is the only other one to have been there, done that.
But Rhyne Williams, it turned out, was unruffled by Del Potro's presence on the same court as him, taking a set off the Argentine before the fifth seed prevailed 6-7(1) 6-3 6-4 6-4 on Wednesday.
A 22-year-old qualifier who hails from Tennessee and one of the many US college tennis players on tour, the bearded American surprised both Del Potro and the Margaret Court Arena crowd with that first set, having recovered from a break down to pinch it 7-1 in a tie-break.
If being a set down in the first round of a Grand Slam made Del Potro see as red as the colour of his shirt, to Williams's credit, he was no one-set wonder. Just three breaks of serve decided the match for Del Potro, and he had to work more than hard for every one of them.
"I didn't expect this kind of matches against him. I didn't know too much before the match how he's playing tennis," Del Potro admitted.
"But he serve well. His forehand is good. I start the match really, really slow, and then was difficult to come back and play my game.
"But in the end, I serve well. I hit some good forehands. That's help me to improve a little bit my game.”
Williams showed how Del Potro can be exploited, achieving that rare thing against a big hitter: out-hitting him. Thundering down 29 aces to Del Potro's 16 and 55 winners to 46, he took the match to a player ranked 125 places above him.
Where Williams let himself down was in the unforced error department, 39 of them to Del Potro's 29. He struggled when the rallies went long, an encouraging feature for supporters of the Argentine, who have long believed that when he displays stamina from the back of the court, he is among the best in the world from the baseline. Even in the heat, which he admitted was a struggle.
"I mean, it was for both player, but is tough to play long rallies, to manage the weather conditions. It’s tough to play in these kind of conditions," Del Potro said.
"I mean, you are thinking about a lot more things than the tennis match. You are trying to drink a lot and always thinking about your body, your physic, and not about the game.
"I know tomorrow and after tomorrow it's going to be worst, so I will try to be ready for the weather conditions, too."
Thus, while it was not the easiest of tussles, it is one that bodes well for Del Potro. He sits in a tricky part of the draw, in Rafael Nadal's quarter, with Grigor Dimitrov his potential fourth round opponent before that.
It is counter-productive to say what could happen in four matches' time. But, suitably warmed up for the fight, there seems to be no reason why, should they collide in the last eight, Del Potro could not reverse what happened the last time he and Nadal met, in the fourth round at Wimbledon in 2011. He is an altogether more complete and confident package than he was then.