Teen star Gauff into Auckland WTA final

A chilled-out Coco Gauff is through to her fourth career WTA final after routing Danka Kovinic in straight sets in Auckland.

The world No.7 won through to her first decider since last year's French Open with a 6-0 6-2 defeat of the Montenegrin on Saturday.

Her opponent will be surprise finalist Rebeka Masarova, who beat Ysaline Bonaventure 6-3 6-3 to make her first WTA final, doubling over in delight at her win.

After a week of heavy rain that forced much of the tournament inside, the skies cleared for semi-final day, allowing tennis-starved fans to return to the ASB Classic.

They witnessed top seed Gauff in determined form, cleaning up Kovinic in just 73 minutes and declaring herself delighted with her form.

"Some of those shots I was like 'OK, that was pretty good'," Gauff said.

"It was a really great match honestly on my behalf. I have nothing to complain about."

The 18-year-old rattled through the first set in under half an hour, serving strongly in a set that was played on her racquet.

After the match, the popular American revealed she was intent on taking less stress onto court this year, as one point showed.

At 3-0 and with a break point, Gauff mishit a drop shot into the net before turning and smiling to the crowd.

"The execution was horrendous," she said afterwards.

"I'm trying to work more on just enjoying the moment. If that was practice I would have laughed at that shot.

"I'm trying to crack more smiles on the court - when acceptable obviously - and in that moment you can't do anything but just laugh at it."

While some athletes try to block out noise and instead zero in on the task, Gauff said she was taking in all the sights and sounds of the tournament.

"On the changeover they had the little Kiss Cam. I was watching it! I'm not going to go as far and probably cheer ... but I'm allowing myself to enjoy the outside moments."

Kovinic showed pluck in the second set, using drop shots to get back in the contest and breaking Gauff early.

However, she gave away her service in the next game with a double fault, keeping Gauff in control.

After saving three match points in the final game, Kovinic succumbed to the inevitable, putting Gauff one win away from her third career title.

Gauff said it "meant a lot" to make the final.

"Especially in the first week of the year. I didn't expect this outcome coming into the tournament but I couldn't ask for a better start to the season regardless of the result tomorrow," she said.

The victory was Gauff's fourth straight-sets win in Auckland, with two matches played on inside training courts without fans due to rain.

Gauff will be heavily favoured on Sunday against Masarova, the world No.130, and 2016 junior French Open winner, who will compete in her first final.

Masarova won through qualifying to take her place in the main draw and beat second seed Sloane Stephens in the first round.

The 23-year-old was too consistent for the error-strewn Bonaventure in her semi, winning in 67 minutes.