Tennis: Caroline Wozniacki gives 'tennis lesson' as she coasts into semi-finals

In the context of what has happened so far this week at the ASB Classic, today's semifinal between Caroline Wozniacki and Sloane Stephens feels like a genuine Clash of the Titans.

With six seeds gone by Wednesday, and three qualifiers reaching the last eight, it has been a tournament of the unexpected.

But yesterday followed the script, with fifth seed Stephens and world No 17 Wozniacki advancing past lesser-ranked opponents to set up a marquee clash in the last four.

The other semifinal between Tamira Paszek and Julia Goerges struggles in comparison, though Paszek's story has been captivating.

It hard's to know what might unfold today. Stephens has improved steadily across the tournament, and yesterday's 7-6 (6) 6-3 win over Brit Naomi Broady was her best performance of the week. But after a wobbly start in the first round, Wozniacki has been ruthless in her last two matches, destroying solid opponents with clinical tennis.

You could even detect some sympathy among the Stanley Street crowd for world No 69 Alexandra Dulgheru in yesterday's quarter-final, as the Romanian was given no chance to get a foothold in the match, thrashed 6-1, 6-0 in 52 minutes. Wozniacki was hitting lines at will, served impeccably and came up with some crushing returns in a display characterised as a tennis lesson by one television commentator.

ASB Classic schedule:
Centre court - 3pm
Danka Kovinic (MNE)/Barbora Strycova(CZE) v Marina Erakovic (NZL)/Silvia Soler-Espinosa (ESP)

Not before 5pm
[Q] Tamira Paszek (AUT) vs Julia Goerges (GER)
[3] Caroline Wozniacki (DEN) vs [5] Sloane Stephens (USA)

Stephens' match with Broady, who has been at the centre of drama in this tournament, first with a win over Ivanovic, then with 'Racquetgate' on Wednesday, was more of a contest.

For the third time this week, Broady raised her level well beyond that of a world No 122. She served big, and gained great profit at the net. In the key moment of the first set tiebreak, Broady couldn't convert her second set point, Stephens subsequently did and it was downhill for the Englishwoman from there.

Wozniacki has an impeccable 5-0 record against Stephens, and has yet to concede a set against the world No 30.

"I've played really well against her in the past but it is a new year, a new tournament, and it's never been easy against her," said Wozniacki. "Hopefully I can keep my level of play."

However, Stephens, after a career marked by a swift rise which saw her become the youngest teenager in the top 50 followed by something of a plateau, appears to be entering the next phase.

Things turned in the second half of 2015. After losing four semifinals, she made her first final at the Citi Open - and won it. Before that week, she had not won any of her 84 tournaments, which made her unique among the top 30 players.

In the other matches yesterday, Paszek outlasted Kirsten Flipkens 6-4 6-7 (3) 6-3 in the first quarter-final, in a match that stretched almost three hours. Then Goerges prevailed over Japan's Nao Hibino 7-6 (3) 6-2 6-4. Goerges, who has been as high as No 15, always looked the likely winner but took a while to get going.

Meanwhile, Danka Kovinic and Barbora Strycova beat fifth seeds Anna-Lena Groenefeld and Coco Vandeweghe 7-6 (5) 3-6 10-6 in last night's late doubles match and will face Marina Erakovic and Spanish partner Silvia Soler-Espinosa in today's semifinals.