There is certainly never a dull moment around the extrovert German-based woman who is given to laughing at her own errors and dancing in celebration of each win. Her fast-improving tennis also has an extrovert feel to it, a refreshing mix of powerful ground strokes and attacking net play.
It is a combination that propelled her to the title in Strasbourg, the final in Brisbane and semis in Miami, Carlsbad and Cincinnati.
Even more impressive, she reached not just one Grand Slam quarter-final but three of them. It was the most recent, the US Open, which helped her make the break into the top 10.
Petkovic was back on court last week for the first time since New York in the last Premier Mandatory of the year in Beijing. A win would deliver her biggest title so far and propel her to No8 in the race to Istanbul.
But despite taking the scalps of many of the top women in the game this yearâ€”Marion Bartoli, Petra Kvitova, Maria Sharapova, Caroline Wozniacki, Jelena Jankovic, Anastasia Pavlyuchenkovaâ€”one player has constantly resisted her attack.
That player comes in the shape of the quiet, slight figure of Agnieszka Radwanska. Ahead of Beijing, the Polish woman had played and beaten Petkovic four timesâ€”twice this year.
Radwanska is an experienced presence on the tour: She turned pro six years ago having won both the Wimbledon and French junior titles. She broke into the top 10 in 2008 after reaching the quarters in the Australian Open and Wimbledon.
But despite a career high of No8 in February 2010, she ended last year at No14 and without a title since Eastbourne in June 2008.
But just as Petkovic has blossomed this year, so Radwanska has enjoyed a second blooming: the quarters of the Australian Open, semis in Stuttgart and Toronto, titles in Carlsbad and Tokyo. Extraordinary, then, that the â€œold handâ€ is the younger of the two women. Radwanski is, in fact, just 22.
Things were looking bright for the Pole ahead of the US Open until she was forced to pull out of Cincinnati with a shoulder injury. When she went on to lose in the second rounds of New Haven and New York, her chances of qualifying for her third WTA Championships began to look slim.
In the Asian swing, though, she bounced back with a vengeance to win the Tokyo title and then raced into the Beijing final without dropping a set. Back up to 10th in the race, the Chinese Open title could all but seal her Istanbul place.
Against her, however, Petkovic boasted a 54-17 win-loss record and, fresh from her US Open quarter-final, was sitting one place above Radwanska in the race. A win could also confirm her trip to Istanbul.
So the stakes were high, but the standard of the tennis turned out to be even higher, as the two contrasting figures contested one of the finest womenâ€™s matches of the year.
It looked at first as though Radwanska would run away with the match. She won the first eight points to lead 2-0 with a mix of aces, smashes, squash-style defence and an unorthodox but searing forehand. It was the same confident, varied tennis that had got her thus far and initially it floored Petkovic.
But at two breaks and 1-4 down, the tall German began to find her range. Winners came thick and fast from both of themâ€”12 apiece after just five gamesâ€”and every rally was long, taxing and high quality. Indeed Radwanska made no unforced errors throughout the opening six gamesâ€”over half an hour.
The crowd cheered every point, and rightly so.
With Radwanska serving in the eighth, however, disaster struck as Petkovic grasped her knee in pain. She struggled to her chair in tears to await the medic but, with knee strapped up, she went on.
The disruption seemed to disturb Radwanska the more: She went down 0-40. She saved two of the break points but conceded the third: It was 4-4.
The match, though, was only just beginning for, by now, games were averaging around five minutes apiece. Radwanska attacked through three deuces to halt the Petkovic run with a break only to see her opponent return the favour in a succession of 20-stroke rallies.
But at 5-5, Radwanska produced a couple of touch volley winners, broke again and served out the set 7-5.
The statistics proved what everyone already knew: This was top-notch stuff. The set had lasted almost an hour and half yet the Pole had made just four unforced errors, 20 winners and 15 from 18 net points. Petkovicâ€™s winner count was 25 with 20 successful net plays out of 26.
If fans thought they had been suitably rewarded already, there was still more to come. Petkovic launched a blistering attack to break Radwanska with a forehand like a jack-hammer.
She smashed and rallied her way to a 6-0 second set in just 25 minutes. Her first serve rate went up to 82 per cent and she made 12 out of 12 winners at the net.
Playing her 11th match in under a fortnightâ€”and now heading into the third hourâ€”Radwanska might justifiably have begun to tire but that would be to underestimate the focus and fitness of this slender woman. She broke Petkovicâ€™s opening game only to hand the break back with a dreadful overhead smash.
Neither woman held serve until the fifth game: It was Petkovic who went 3-2.
Radwanska had not held serve since she took the opening set, but now she did. Her unconventional forehand came back into play as she passed a net-rushing Petkovic with a cross-court winner, and a second forehand forced the break. She held her nerve, found her serve and took her victory in style, 6-4.
It was a match that had it all: touch volleys, power forehands, tactical intelligence, long and complex rallies, and two women whose contrasting personalities captured the fansâ€™ imagination with their exciting tennis, energy and sporting spirit.
On this occasion, it was Radwanska who prevailed. Only Marion Bartoli can overtake her in the race to Istanbul and the French woman will have to win titles in both Osaka and Moscow to stand a chance. Even so, Bartoli would need Radwanska to fall before the Moscow quarter-finals.
But it could just have easily been Petkovic who confirmed a place in her first WTA Championships. At it is, she will take one of the two reserve spots.
Next time, it could be different, as it very nearly was in Beijing. For after more than two-and-a-half hours, Radwanska and Pekovic were separated by just one point: 100 to 101.
Caroline Wozniacki, Race points 7,395, WTA ranking 1
Maria Sharapova, Race points 6,370, WTA ranking 2
Petra Kvitova, Race points 5,691, WTA ranking 4
Victoria Azarenka, Race points 5,590, WTA ranking 3
Na Li, Race points 5,351, WTA ranking 7
Vera Zvonareva, Race points 5,190, WTA ranking 5
Samantha Stosur, Race points 4,975, WTA ranking 6
Playing Osaka and Moscow
Favourite to qualify:
Agnieszka Radwanska, Race points 4,940, WTA ranking 8
Andrea Petkovic, Race points 4,580, WTA ranking 9
Playing Linz and Luxembourg
Marion Bartoli, Race points 4,455, WTA ranking 11
Playing Osaka and Moscow
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