Having beaten Maria Sharapova for an 18th time in a row, Serena Williams has again moved to within two victories of matching the Open-Era record of 22 Grand Slam titles. Williams triumphed 6-4 6-1 in the Australian Open quarterfinals on Tuesday; a match that was harder fought than the scoreline suggests but still maintained her dominance in the most high-profile and most one-sided rivalry in women’s tennis.

And now she is back in the final four of a Major and looking to quash the agonizing memories of the last time she reached this stage. Then a calendar-year Grand Slam was in her grasp, only to slip away in stunning fashion as the emotional impact of such an achievement took its full toll in a huge upset loss to unseeded Roberta Vinci at the U.S. Open.

When Williams arrived in Melbourne two weeks ago, that defeat remained the last match she had completed on tour. After sitting out the rest of last season, citing various physical ailments but surely also recovering mentally, the world No. 1 then retired with a knee problem on her return at the Hopman Cup.

Understandable doubts hung over her head as the first Grand Slam of 2016 got underway. Yet, not for the first time, Williams has convincingly answered question marks over her fitness and match sharpness when arriving on the big stage. After a competitive opening round match against Italian Camila Giorgi, Williams has lost just 13 games, and no sets, in her next four matches.

As incredible as it may be, Williams’ form in Melbourne has been even more impressive than her displays last year. While she may have only lost one Grand Slam match in 2015, she was taken to three sets on 12 occasions. Although clearly superior, Williams often had lapses that allowed her opponent to make the match closer than it should have been.

So far at the Australian Open, though, she has been supremely focused. That shouldn’t be surprising, given she still has plenty to keep her motivated. While at the U.S. Open she failed to match Steffi Graf’s 1988 calendar-year Grand Slam, she has the chance in Melbourne to join the German great on 22 Grand Slam titles, second only to Margaret Court’s all-time record of 24.

Two matches still remain before that ambition becomes a reality, however. Standing in her way next is a player who will pose a very different test to that offered by Sharapova. Semifinal opponent Agnieszka Radwanska is one of the few players to buck the modern dominance of power-hitting in women’s tennis. Instead, the Polish fourth seed prefers to dissect her opponents with a thousand cuts, using her craft and variety as well as exceptional court sense.

And she has been in fine form in recent months. After ending 2015 by winning the WTA Finals, she started 2016 by picking up the title in Shenzhen, China. And she has impressed en route to her fifth Grand Slam semifinal, dropping just one set and cruising past 10th seed Carla Suárez Navarro in the quarterfinals.

Her record against Williams, though, does not make for comforting reading. The 26-year-old has lost all eight of their meetings, and won only one set along the way. That single set triumph came following her only successful navigation through the last four of a Grand Slam, when she came out on the losing end to Williams in the 2012 Wimbledon final.

Also counting in Williams’ favor is the fact that on each of the six occasions that she has reached the last four of the Australian Open she has gone on to claim the title. Still the 34-year-old insists she expects a tough contest against Radwanska on Thursday.

“It will be a good match,” she said. “She's been playing really well towards the end of the year, and already this year she's been very consistent. She presents a completely different game, an extremely exciting game. So I think it will be a long match and it will be a good match to see where I am.”