In an extraordinary twist, ageless champion Roger Federer is suddenly the new Australian Open favourite - not that the man himself seems overly surprised.
The 35-year-old father of four is contesting his first official tournament in six months following an injury-enforced layoff.
But after backing up his third-round schooling of 10th seed Tomas Berdych with a 6-7 (4-7) 6-4 6-1 4-6 6-3 defeat of fifth seed Kei Nishikori on Sunday night, Federer now has the backing of bookmakers around the world.
The Swiss great's vintage form and the shock exits of Andy Murray and six-times champion Novak Djokovic - marking the first time in 15 years the top two seeds have bowed out before the quarter-finals - left Federer as Open favourite at the tournament's halfway point.
Such a scenario was unimaginable a week ago as Murray, the newly-knighted and newly-elevated world No.1, and Djokovic arrived in Melbourne eyeing their own special places in tennis history.
Federer was unsure what to expect entering his 18th Open with an unfamiliar 17th seeding.
But as he grows in confidence, no longer concerned about his once-suspect knee, the 35-year-old says he's not surprised he and great rival Rafael Nadal made the final eight.
"I felt like if Rafa and myself can be healthy, yes, you can expect that," Federer said ahead of Tuesday's quarter-final against Murray's fourth-round conqueror Mischa Zverev.
"That Novak and Andy are not, that is a big surprise. I never thought that Mischa Zverev and Denis Istomin would beat those two big guys.
"I guess it's good for tennis that a lot of guys believe stronger now that the top guys are beatable, are vulnerable, especially on a faster court."
Federer crushed Zverev 6-0 6-0 the last time they clashed, but knows the German left-hander is a different proposition four years on from that grass-court match-up in Halle.
"Obviously he's on a high right now. He's feeling great. Probably feels the best he's ever felt on a tennis court," Federer said.
"That's how I would feel after the win today against Murray.
"It's going to be tough and different and tricky. That's my mindset."
Hunting down an elusive 18th grand slam crown - five years after landing his record 17th - Federer could strike fourth-seeded countryman Stan Wawrinka or Jo-Wilfried Tsonga in the semi-finals.
