London:Lleyton Hewitt believes he can still punch his weight with the Wimbledon heavyweights and defy the critics who insist the game has passed him by.
The 28-year-old Australian, a former world number one and the doting father of two toddlers, is enjoying a new lease of life having undergone successful hip surgery last year.
He has reached the last 16 at Wimbledon, without dropping a set, for the sixth successive year and next faces tricky Czech serve-and-volleyer Radek Stepanek for a place in the quarter-finals.
It's the kind of form that has stunned those who thought the likes of Roger Federer and Rafael Nadal had set the bar too high for the tenacious Australian.
"When I look at the guys in top five, top 10, I still feel like I'm good enough to be up there, that's the motivation," said Hewitt, who eased into the last 16 with a 7-5, 7-6 (7/3), 6-3 win over Germany's Philipp Petzschner.
"Playing in these tournaments, when you are growing up, these are the places you want to play at. I've been fortunate enough to play well at a lot of these big events.
"The passion and hunger's still there. The day that's not there, it is time to hang up the racquets."
Hewitt, however, is not getting carried away by the business of rebuilding his ranking from its current lowly 56, a legacy of his lengthy time away from the circuit.
"At the moment, it's more focusing on the Grand Slams and trying to get the best out of myself at the Slams," he said.
"If I'm able to do well at those, the ranking will take care of itself. Obviously, I'd like to get back in the top 20 as soon as possible."
Hewitt has defeated Stepanek in both their previous meetings with the Czech failing to win a set, but the pair have not met for six years.
Stepanek's hopes of preventing Hewitt from booking a place in the quarter-finals for a fifth time have not been helped by a knee injury which will require his doctor to fly from Prague to inspect the damage.
"I think Lleyton is playing great tennis right now, especially here at Wimbledon," said Stepanek who made the last eight in 2006.
"He has won it here, so definitely he's got the experience. It's going to be a tough match. He's a great returner. He's passing great. So it will be an exciting match.
"If you're not hundred percent fit, he's going to make you run like a horse."