It’s not like six-times champion Serena Williams needed to put her Australian Open rivals on notice.
Nobody doubted Williams’ status as title favourite before she thumped Maria Sharapova 6-4 6-1 on Tuesday, advancing to a semi-final against Agnieszka Radwanska on Thursday.
There were also no caveats about Williams’ hopes of equalling Steffi Graf’s open-era record by winning a 22nd grand slam title at Melbourne Park.
And yet by playing below her best in a quarter-final against Sharapova, Williams delivered a timely reminder of her talent ahead of Saturday’s decider.
An untimely bout of food poisoning should have given Sharapova hope of stopping Williams’ run of head-to-head dominance at 17 matches.
Instead the powerful American sent down the fastest serve of the tournament at 202km/h and blasted her opponent off the court in an hour and a half.
“I was just dealing with some food-poisoning issues,” Williams said, when asked why she consulted a doctor throughout a lopsided second set.
“Yesterday it was worse.
“I was a little lethargic (in the first set) I just started slow. I missed three or four easy shots.
“When you’re playing someone like that you have to come out with a lot of fire and intensity.
“I didn’t start out playing that way.”
Sharapova hadn’t beaten Williams since 2004 but started the 2015 Open final rematch in fine style.
Williams dropped four straight points to be broken in the opening game, with Sharapova holding for a 2-0 lead.
The response was as powerful as it was predictable.
Williams steadied, while Sharapova twice double-faulted en route to 0-40 but won the next five points to make it 4-4.
For the first time in the tournament, questions were being asked of Williams.
The 34-year-old stared down two break points in a 14-point service game, finally edging ahead for 5-4.
Williams broke for a second time to take the first set in 55 minutes but only after the top seed had mucked up three set points, twice thundering returns into the net.
Williams called for the trainer at the break then bossed Sharapova around the court, grabbing a 5-0 advantage as the Russian surrendered meekly.
“I knew I just wanted to start playing the way I had been, which got me to the quarter-finals,” Williams said of her second-set rampage.
Sharapova tried to stay positive after her 19th loss to Williams.
“It’s motivating because she’s at a different level,” the five-time grand slam winner said.
“She makes you go back to the drawing board, not just for me, but for many other players.
“She makes you work.”
Earlier on Tuesday, Radwanska became the first woman through to the Open semi-finals when she defeated Spaniard Carla Suarez Navarro 6-1 6-3.
Fourth seed Radwanska will be looking to erase memories of her previous best finish at Melbourne Park, a 2014 semi-final loss to Dominika Cibulkova that lasted just 70 minutes.
Williams has won all eight clashes with Radwanska on tour, including the 2012 Wimbledon final that went three sets.
“She got the better of me at Hopman Cup. It will be a good match,” Williams predicted.