MELBOURNE, Australia - Latisha Chan scored a Grand Slam victory at the expense of her sister for the second straight major on Monday afternoon, as she and Andrea Sestini Hlavackova partnered for a 6-3, 6-2 win over Chan Hao-ching and Katarina Srebotnik in the fourth round of the Australian Open.

The elder Chan sister, as the No.2 seed at the US Open last summer alongside Martina Hingis, defeated her younger sister and Zhang Shuai in the quarterfinals en route to the pair's first Grand Slam before Hingis' retirement at the BNP Paribas WTA Finals Singapore presented by SC Global.

"I try to just keep calm and see her as another opponent - I think that shows respect to the others," the elder Chan said on-court after the match.

"We grew up together and our coach is our dad, so basically it's a family business. I'm very happy that I went through with Andrea, and we're looking forward to our next round."

On Monday in Melbourne, the top-seeded Latisha and Sestini Hlavackova never trailed after an opening service hold by the No.14 seeds to reach the last eight in their first Grand Slam as a team. 

With her team trailing 3-6, 1-4, Chan Hao-ching left the court for a medical timeout, and upon resumption, Srebotnik held at love to secure just their second game in eight.

However, the top seeds wrapped up the match in short order, as they won the last two games and eight of the last 11 points. 

"I hope the game is good for [the fans] to watch, and I hope my sister doesn't hate me after this!" Chan joked to the crowd.

No.6 seeds Gabriela Dabrowksi and Xu Yifan ran their winning streak to six straight matches to begin 2018. (Getty)

Sydney International champions and No.6 seeds Gabriela Dabrowksi and Xu Yifan continued to roll, as they won their sixth straight match in straight sets to begin the season and reach the quarterfinals. 

Though the Canadian and Chinese pair led by a break twice in the opening set, they were forced to save a set point before rolling past No.11 seeds Shuko Aoyama and Yang Zhaoxuan, 7-6(6), 6-1. 

No.2 seeds Elena Vesnina and Ekaterina Makarova had a contrasting win to their top-seeded counterparts, as they survived the Czech pairing of Barbora Krejcikova and Katerina Siniakova in nearly two-and-a-half hours, 7-6(2), 6-7(5), 6-2.

The Russians twice trailed by a break in the opening set, needing to come up with their vintage best to keep the opener alive in the 10th game before winning it in a tiebreak.

Though the No.16 seeds also led by an early break in the second set, Krejcikova and Siniakova needed to edge out a tiebreak of their own to force a decider. Nonetheless, Makarova and Vesnina used an early 3-0 lead to set the tone for the deciding set, and keep their dreams of completing the career Grand Slam in Melbourne alive. 

Finally, No.5 seeds Kristina Mladenovic and Timea Babos kept moving into the quarterfinals with a 7-5 6-2 win over Viktorija Golubic and Nina Stojanovic. The two rallied from 4-1 down in the opening set and saved a set point en route to the victory.