4 reasons why Serena Williams is in TOP form

Serena Williams is playing tennis on another level compared to the rest of the women's field, according to Agnieszka Radwanska who suffered a 6-0, 6-4 rout at the hands of the American in the Australian Open semi-finals on Thursday.

Serena demolishes Radwanska to make seventh Australian Open final

The 26-year-old Radwanska lost the first set in just 20 minutes on Rod Laver Arena before she got some momentum back in the second set but was unable to stop Williams' march to her seventh final at Melbourne Park.

1. "She goes on court and she just wants to kill it," Radwanska told reporters after her 64-minute loss at the hands of the World No 1.

2. "There was just no mistake. Unbelievable serve. Everything, she was going for it. Yeah, I couldn't do much. Not at all, actually.

"I don't think anyone can really play on that kind of level at all."

Radwanska had been bidding to advance to her second Grand Slam final, after Wimbledon 2012, but once Williams broke in the first game the writing appeared to be on the wall.

Radwanska's fastest serve in the first game topped out at 140kph. Williams, who blasted 42 winners in all, was sending it back at more than 130kph.

3. "I think she started unbelievable, with such a power and speed. I was just standing there kind of watching her playing," Radwanska added.

"When I was serving, everything is just going to your side with that kind of power, so deep that you cannot do anything."

The loss was Radwanska's second at the semi-final stage of the Australian Open, having also been hammered by Dominika Cibulkova 6-1, 6-2 when a heavy favourite in 2014.

4. Despite losing her perfect start to the 2016 season having won at Shenzhen before the Australian Open, Radwanska said she could still take positives out of the tournament, given she felt nobody could have stayed with Williams on Thursday.

"Semi-final of a Grand Slam isn't a bad thing. Still very happy with the result, happy with my game, for all the matches here," she said.

"I'm not even angry because I know she was just playing too good today."