MELBOURNE -- Hsieh Su-Wei was nowhere near a tennis court this time last year. Asked what she was doing twelve months ago, Hsieh responded by mimicking a slalom skier.

"I was doing classes to improve my ski skills," Hsieh told WTA Insider.

Mertens chimed in: "You can see it definitely helped her tennis."

Hsieh laughed. "Yeah, I worked harder than in tennis, sorry."

"The coaches took me to the mountains and I said no, no, no, I can't do this. When he took me to one that was very dangerous, I screamed 'No, don't stay so far from me.' That was very scary. I was freaking out.

"I just started, so I just want to survive."

Without missing a beat, Mertens had a realization. "So that's why there's no stress at 5-all," the Belgian quipped.

Hsieh and Mertens capped off a doubles run on Sunday at the Australian Open after capturing their second team title and first since their reunion. For Mertens, the win consolidated her return to the top of the doubles rankings, as the 28-year-old captured her fourth major doubles title and first since winning 2021 Wimbledon with Hsieh. 

For Hsieh, 38, the title added to the lore that surrounds her return to competition. After sitting on the sidelines for 16 months to let her body rest, Hsieh returned to the Hologic WTA Tour last spring and has proceeded to snap up Grand Slam titles as if she never left. 

With wins at Roland Garros, Wimbledon, and now the mixed doubles and doubles titles at the Australian Open, the former No.1 now holds three of the four Grand Slam titles. Along with her mixed win with Poland's Jan Zielinski, Hsieh's four titles were all won with four different partners. 

That's a far cry from where things began. Hsieh came back last spring to help celebrate Barbora Strycova's retirement tour. But when she reached out to find partners to play other events, her text messages landed on reluctant ears.

"Many people think I come back great, winning all the tournaments," Hsieh said. "But no, no, all the girls were refusing me. Until one day I play with Barbora [at Wimbledon] and Wang Xinyu for the Roland Garros, and then the situation become better."

Mertens was fortunate to reunite with Hsieh in 2024. She approached Hsieh to re-team for the new year and happened to be at the front of the queue. 

"You were asking very early so it was good," Hsieh said. "Because there was some girl asking me, I say, 'Oh, sorry, I already answered Elise.'"

Mertens was coming off an outstanding season with Storm Hunter, who finished the season at No.1. When the two split, Mertens was more than happy to pair up again with one of the most unpredictable personalities in tennis.

"Expect the unexpected," Mertens said. "I know her and she knows me. We're very open to each other and the game we want to play. It doesn't matter if we make mistakes. If we do the right thing or try to do the right thing, no problem. 

"It's very fun to play with her. She's amazing at the net. Especially her mentality when we have to have the point. But yeah, I like the unexepcted sometimes. It's very fun."

Hsieh knows she can be the biggest variable on any court. As a singles player, she baffled some of the biggest hitters with her craft and guile, and she continues to do so on the doubles court. In Sunday's final, she had little problem handling the pace coming off Jelena Ostapenko's racquet, whether at the baseline or the net.  

"Sometimes I play by my mood, sometimes I play depending on the partner," Hsieh said. "Sometimes I try to control my partner. Sometimes I tell them they can control me, but sometimes they look confused. You always have a different strategy of what you can do." 

Hsieh played her last Grand Slam singles tournament at the Australian Open, but she will continue to play on the doubles tour. Her primary responsibility will be supporting Mertens at the tour's biggest tournaments, with a focus on the Grand Slams. Apart from that, Hsieh will simply adapt as the situation demands. 

"Same for me," Mertens said. "The goal is to play big tournaments, but the smaller ones, the 250s or 500s, I'm not planning to play a lot of doubles. 

"I'm focusing on the big boys."