Moeen Ali chose a fine time to make both personal and cricket history after his first hat-trick at any level sealed England's 239-run win in the third Test against South Africa at The Oval.

A match imbued with historical significance -- this was the 100th Test at The Oval -- saw off-spinner Ali create some of his own.

His was just the 14th England hat-trick at this level and the first in south London ground The Oval's 127-year history as a Test venue.

Dean Elgar did his best to prevent England going 2-1 up in this four-match series with a gutsy innings of 136.

The left-handed opener was, however, the first of Ali's hat-trick victims on Monday's fifth day, edging to Ben Stokes at first slip.

Kagiso Rabada exited in similar fashion next ball but that was the end of the over.

But with South Africa surviving the ensuing Stokes over, it was left to Ali to have last man Morne Morkel lbw with his next delivery.

It needed an England review of West Indian umpire Joel Wilson's not out decision, however, to confirm that the Proteas, set a mammoth 492 for victory, were all out for 252 after lunch on Monday's fifth and final day.

"I've never taken a hat-trick in any sort of cricket," said the 30-year-old Ali.

"I've scored a few hat-tricks in football warm-ups, but this is a different sort of feeling ... a better feeling."

England captain Joe Root added: "It was a special way to finish, and quite a fitting one in the 100th Test here, and summed up a really good week for us."

Ali, England's lone specialist spinner at The Oval, has now taken 18 wickets this series and 116 in his Test career in total.

- 'Less pressure' -

Not that England will care if Ali, who had innings figures of four for 45 on Monday, keeps taking wickets.

"Mo quite likes having that feeling of having maybe a little bit less pressure," explained Root.

"When we need to take wickets in the fourth innings of a Test match, he's able to do it," he added.

Several former England captains had slammed Root's men for an inability to graft out a score during a 340-run thrashing by South Africa in the second Test at Trent Bridge.

But with all-rounder Stokes, the man-of-the-match, making 112 in a first innings 353, England established a commanding position at The Oval that they never let slip.

"It was obviously a difficult week up in Nottingham, but the way the guys responded and character they showed to come back was outstanding," said Root after just his third Test as captain.

But if the pattern of this see-saw series continues, South Africa should secure an equally huge win in the fourth Test at Old Trafford starting on Friday.

"We've not done things by halves so far in this series," Root admitted.

"It's just important that we take (with us) the way we've played this week -- especially the way we batted, which I thought was exceptional."

Stokes led the way and Root said: "He thinks really well and he's got a great cricket brain, which he doesn't always get a lot of credit for.

"He's a person you know you can turn to under pressure to wrest a game back in your favour."

Elgar battled hard to keep England at bay during an innings where he copped both physical and verbal blows.

"It's part of the game - you have to roll with the punches and take the blows when they come your way," he said.

As for the 'verbals', Elgar insisted he "enjoyed it", adding: "England are a big huff-and-puff bowling attack and when they are on top, they are definitely going to bring their mouths as well.

"If the shoe was on the other foot I'm sure we'd be doing the same thing."