In doing so, the 30-year-old became the oldest woman to reach the final since Steffi Graf in 1999 and only Poland’s Agnieszka Radwanska, who beat Germany’s Angelique Kerber 6-3 6-4, stands between her and a fifth All England Club title.

The 15,000 fans packed into a sunny Centre Court gasped in awe as each Williams thunderbolt flew past the Belarusian.

To her credit, Australian Open champion Azarenka stood firm in the face of the heavy fire and she would have earned plenty of new admirers in a 6-3 7-6 defeat.

The 22-year-old second seed even had the temerity to break the Williams serve midway through the second set as she dragged the contest into a tiebreak, but she was finally overwhelmed.

Since Williams won the last of her 13 grand slam singles titles at Wimbledon in 2010 she fell into a pit of despair after a gashed foot and subsequent serious health problems threatened to end a golden career.

Even the often controversial American’s harshest critics would readily concede they are pleased she is back, still hungry for titles and strutting around on Centre Court’s hallowed turf.

Those trying to avoid actual bodily harm trying to return her cannonball serve may not agree, but Wimbledon would be a poorer place without her.

After patchy performances in the early rounds, Williams changed gear against defending champion Petra Kvitova in the quarter-finals and during a clinical first set against Azarenka, she was virtually unplayable.

She began the third game with three consecutive aces before Azarenka somehow got her racket to the fourth. The game took barely a minute to complete.

Azarenka, who caused chuckles from the crowd with her mighty grunts every time she struck the ball, dug deep from a break down in the second set and pierced Serena’s armour to level at 3-3.

Showing tremendous fight she saved three break points in the next game and for the first time Williams looked ruffled.

KNOCKOUT BLOW

Williams edged ahead in the tiebreak with a 23rd ace to equal her Wimbledon record, and despite wasting a match point with a lob that sailed long, she made no mistake on the second, her trusty weapon delivering the knockout blow.

Ever the perfectionist, Serena, who later reached the women’s doubles semi-finals with sister Venus, told reporters: “It didn’t feel like I hit 24 aces. I actually felt my serve was off, but maybe it should be off a little bit more.

“I was just out there trying to play my game which is pretty aggressive.”

Asked to describe her first serve, however, her reply was “mean”.

Radwanska, who not only will contest her first grand slam final on Saturday but could also claim the No. 1 ranking if she wins, may want to avoid watching a Williams DVD before bedtime as she prepares for the biggest day of her career.

Williams hit more aces in one set on Thursday than the Pole has struck in the entire tournament.

The former Wimbledon junior champion, who has become the first Pole to reach a grand slam final since Jadwiga Jedrzejowska at the French Championships in 1939, is not known for a power game, more the accuracy and intelligence that proved too much for Germany’s Kerber.

The third seed slipped 3-1 behind in a nervy start to her first grand slam semi-final but soon had Kerber on the run with her superior courtcraft.

After sealing the first set with an ace, Radwanska broke again early in the second and never remotely looked like relinquishing her lead.

“I’m the first (Polish) player to win in a semi-final for many years, so I think this is already a big success,” Radwanska, who lifted the junior title in 2005, said.

“And now here in the final, it’s even bigger. This tournament is already one of the big part of tennis history in Poland. I’m happy to be part of that.”

Another player with his eye on history is Briton’s Andy Murray who will start as favourite to beat Frenchman Jo-Wilfried Tsonga in the second of two juicy men’s semis on Friday.

Murray mania is expected to grip the nation when thousands of fans without showcourt tickets are expected to flock to the club’s giant screen on Henman Hill to watch Murray’s bid to become the first British man to reach the Wimbledon singles final since Bunny Austin in 1938.

Should Murray win he would face either defending champion Novak Djokovic or six-times winner Roger Federer in the final. DM

Photo: Agnieszka Radwanska of Poland celebrates after defeating Angelique Kerber of Germany in their women’s semi-final tennis match at the Wimbledon tennis championships in London July 5, 2012. REUTERS/Stefan Wermuth