In echoes of days gone by, both of the Williams' sisters qualified for the quarter-finals at the Australian Open today. Serena's progress was expected if not certain, as the world number one has proved that she is not as infallible as she once was in recent matches in Australia, but she found a way to win through in three sets. In doing so, she had to overcome her Spanish nemesis Garbine Muguruza, who had defeated her at last year's French Open. Venus is essentially a 'wild card' these days and has struggled to reach the later stages of the major tournaments, as she struggles to cope with Sjogren's syndrome, a disease that affects the auto-immune system and often leads to fatigue.

Yet, she rolled back the clock to put out sixth seed Agnieszka Radwanska also in three sets.

Much had been made of Serena's potential 'mental block' against the Spaniard after that defeat in the French, in the run up to their last-16 battle. It had been a major shock when she lost to Muguruza then, but the manner in which she had been defeated in straight sets was an even greater surprise, amid suggestions that Williams had been made to look leaden-footed during that game. The Spaniard is not such a surprise package to the Tennis fraternity nowadays though after moving up to 24th seeding in Melbourne, so a close match was always likely. The portents were not promising as Serena lost the first set 6-2, but she battled back to take the next two sets 6-3 6-2 to at least partially avenge the previous defeat.

She now faces the number 11 seed Dominika Cibulkova in the quarter-finals, after the Slovakian put out the much-fancied dark horse (and former Australian Open winner) Victoria Azarenka.

Venus is now 34 and still a threat on her day for anyone left in the tournament, but has slipped down the rankings to number 18 in the world, as the impacts of Sjogren's syndrome have had to be dealt with.

She went into the match with the Polish sixth seed as the slight underdog, but came through after a second set blip, 6-3 2-6 6-1, showing that her form is returning. In defeating Radwanska she advanced into her first quarter-final in a Slam since 2010, where she will meet her fellow American, the unseeded teenager Madison Keys.

Although neither sister will be looking too far ahead of themselves, they could be in line for a tantalising semi-final pairing should they both advance that far. Now that would make for quite some match, between the seven-time Grand Slam winner Venus and her younger sister who holds 18 Slam titles herself.