PERTH, Australia -- Star power is in no short supply at the inaugural United Cup. But the beauty of the competition's format has been how their lower-ranked teammates have been given a chance to shine on a rare big stage -- and how several of them have grasped this opportunity with gusto to provide some of the group stages' most indelible moments.

In Perth, Greece's No.158-ranked Despina Papamichail was the victor of the city's first rubber over Bulgaria's Isabella Shinikova, and in her second outing thrilled the RAC Arena crowd as she pushed Alison Van Uytvanck all the way in a top-quality three-setter. In turn, No.379-ranked Shinikova had her moment when she peaked in a third-set match tiebreak to win the first ever deciding mixed doubles rubber of the competition, partnering Alexandar Lazarov to upset Belgium's Elise Mertens and David Goffin.

In Brisbane, No.464-ranked Kazakh Zhibek Kulambayeva started the week as an unknown who had only previously played one tour-level match, but ended it as a crowd favourite. Despite her opening loss to Jil Teichmann, the 22-year-old showed enough moxie and bold shotmaking to make an impact -- and her Top 100 teammates were keen to boost her.

A dropshot winner was greeted by a proud Yulia Putintseva grinning from ear to ear, before exhorting the crowd to cheer for Kulambayeva. Playing captain Alexander Bublik applauded her off court following the Teichmann match, and hyped her up throughout their subsequent mixed doubles rubber.

Norway's No.321-ranked Malene Helgo, who had never even contested a WTA qualifying draw before this week, was the next to make her presence felt in Brisbane, keeping Roland Garros semifinalist Martina Trevisan on court for 3 hours and 2 minutes before falling 7-5, 3-6, 6-4.

"I have my eyes wide open. Every day is a lesson for me."

- Despina Papamichail on her United Cup experience with Team Greece.

For the less experienced players at the United Cup, being around their higher-ranked teammates has served as both inspiration and a learning opportunity.

"I have my eyes wide open," Papamichail told after her loss to Van Uytvanck. "Every day is a lesson for me. I'm trying to hear everything, learn from everyone, especially the people who are where I want to be.

"Yesterday, Stefanos [Tsitsipas] was practising for over two hours, and today he had a match. Those things make me realise that it's not a miracle or luck that they are there -- they are working hard. They are giving us advice -- in the match, in important moments Stefanos was telling me to go for it, it's not going to come by itself.

"Generally, being around them helps. You see their character. In this tie [against Belgium], we know we need two points, but Stefanos and Maria [Sakkari] were the first to say, 'Guys, we're going for the tie.' They weren't thinking about just two points -- they are ambitious, and I love it."

Importantly, the feeling is mutual. Tsitsipas, who says that he has followed Papamichail's steady rise up the rankings for several years, was quick to pay tribute to her performance against Van Uytvanck.

"Today I saw Despina, she did some beautiful things on the court, being very creative, and following some really good tactics," he said. "That is inspiring when you see that. You can pretty much learn from everyone."

Tsitsipas' faith in his compatriots was echoed by playing captain Grigor Dimitrov. After Bulgaria's 3-2 upset of Belgium, the three-time Grand Slam semifinalist said that he had wanted each player on his team to have court time -- hence rescinding himself from the mixed doubles decider in favour of Shinikova and Lazarov.

"I just want everybody to get out there on the court and experience just that vibe," he said. "I'm happy that everybody was able to, again, in a way, to participate and give their all."

Dimitrov's approach paid off after Shinikova and Lazarov saved a match point en route to victory.

"I have to thank Grigor for the confidence to put me on the deciding match.," said Shinikova. "I'm really proud of myself that with Alex we play really good. We was like team, the fight experience was really good, and we fight until the end and it's really important for me."

The United Cup experience may not have to be a one-off moment in the spotlight, but an experience that pays off down the line. Bulgaria's No.324-ranked Gergana Topalova made her tour-level debut as a last-minute substitute for Viktoriya Tomova, and after taking Mertens to three sets was heartened to have played a tour stalwart so closely.

"It's the first time I played a player that is in the Top 100," said the 22-year-old. "I thought that the level, it's not that much different and that I have the game to make it also there."

The Croatian team in Perth contains two fast-rising young talents, 20-year-old Tara Wurth and 17-year-old Petra Marcinko, the reigning Australian Open junior champion. Neither are scheduled to play singles, but both say that the experience of being on a team containing sometime Top 20 players Petra Martic, Donna Vekic and Borna Coric, and led by former Roland Garros champion Iva Majoli, has been invaluable.

"It's really motivating for me and the small Petra," said Wurth at the start of the week. "It's amazing to be around these top players and to see how they work, how they play, where can I improve, what more can I learn from them."

Hot Shot: Croatia's Wurth pays off Gojo's tweener

Wurth was able to demonstrate what she'd learned when, playing on the biggest stage of her career to date, she shook off a nervous start to notch a 1-6, 6-4, [10-4] mixed doubles victory over Argentina's Nadia Podoroska and Tomas Martin Etcheverry. Afterwards, she credited partner Borna Gojo and captain Majoli for helping her relax.

"It's my first time playing on a big stadium with that kind of crowd," she said. "First set was tough, but as the match went on, Borna was giving me great advice. He was making me laugh. He was just supportive, and in the end I calmed, I focused on tennis, not on everything that goes around."

Gojo said he had reminded Wurth that this moment was what she had been working towards.

"I told her she should enjoy. It's a big stage, and it's why we all play tennis, to play in the stages like this."

However, the benefits don't flow just one way. Asked about how she had settled into the role of an experienced mentor, Vekic said that she had raised the stakes when playing practice sets with Marcinko and Wurth.

"Petra owes me an ice cream and Tara owes me a manicure now," said Vekic. "So I would say it's working out pretty well for me too!"