On one side of the net was the 23-year-old former world No 1, the highest-paid female athlete on the planet, the holder of three Grand Slam titles, multiple seven-figure endorsement deals and career prizemoney approaching US$14 million ($18.48 million).
On the other, a 31-year old with one career title, slightly more than half a million in prizemoney since 1995 and, as far as it's known, has appeared on no Nike posters or magazine covers.
It was a mismatch of Biblical proportions and so it proved on court, with Maria Sharapova absolutely no match for Greta Arn.
The Hungarian, who divides her time between Budapest and Rome, has only twice ended the year with a ranking in double digits. In 2002 she ended 91 and last year she was ranked three spots higher. In between times she had to take a job in the media - poor thing - after her agent ripped her off and sent her spiralling into debt.
She values every day she plays on this tour now because "I know the other side".
When she arrived here at the end of last month, she did so in the expectation of having to play through the qualifiers, but some late withdrawals allowed her a spot in the main draw.
That guaranteed her a cheque for the week, but didn't expedite the arrival of her luggage, which took eight days longer than her to get here.
Her coach never made it, saying it was too far to come unless Arn could foot the bill. She's hitting up with whoever has the time or the inclination.
So playing Sharapova in the quarter-finals of the ASB Classic was nothing to fear, it was something to embrace and that was seen in her nerveless approach - until the final moments, that is.
"I was just shaking," Arn said. "I didn't feel nervous all game until that last game when it was 'Oh my god, I could beat Maria Sharapova'."
She described her 6-2, 7-5 win as the biggest in her career, at least since the day she beat Mary Pierce in 2002.
As for Sharapova, shed few tears for her - she'll be okay.
When the organisers run through their cost-benefit exercises, the Sharapova signing will probably end up on the positive side of the ledger.
There was all the publicity, a sold-out stadium and some attractive signage, but most of the good came before a ball was hit.
On court, we were treated to three performances that ranged from patchy to listless - not unusual for this time of year, no matter who the player - and the overriding impression this was a chance to have a bit of a hit-up before more important matters in Melbourne.
Certainly her coach was heard on Wednesday telling her it was "practice" and yesterday took the frowned-upon step of removing his microphone before advising Sharapova on matters tactical. Perhaps he realised to be caught saying something like, "Remember to wave to the crowd and let's get out of here", wouldn't have gone down well with those who shelled out for her appearance fee.
While Australia is clearly the big goal for the month, she did have the decency to say it hurt to lose.
"I'm a big competitor. When you're out there you forget where you are, what you're doing. It's just about you and your opponent. It's why I love the sport so much."
New Zealander Marina Erakovic and Swede Sofia Arvidsson make it through to the doubles semifinals.
The pair, playing together in an event for the first time, upset doubles specialists and second seeds South African Natalie Grandin and Czech Vladimira Uhlirova 7-6 (8-6), 6-3.