Simona Halep avoided becoming the first world number one to suffer back-to-back first-round Grand Slam exits with a gutsy three-set win over Kaia Kanepi at the Australian Open.

The Romanian top seed fought back impressively to beat the Estonian veteran 6-7 (2-7) 6-4 6-2 in Melbourne.

The fightback was a measure of revenge after Halep was stunned by 71st-ranked Kanepi at the US Open.

Halep, 27, will face American Sofia Kenin in round two.

“After losing against her in the US Open, it was a bit of pressure on my shoulders,” Halep said.

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Kanepi’s victory in New York was one of the shocks of the tournament, with fate bringing the pair back together at 2019’s first Grand Slam.

Despite the gulf in their respective rankings, another victory for the Estonian may not have been a complete surprise.

In addition to Kanepi already having the measure of Halep, the reigning French Open champion had not won since August in a five-match losing streak, struggled with a back injury in the final part of last season and split with her coach Darren Cahill in November.

“I said I had no expectations coming here,” said Halep, who could lose the top ranking in Melbourne.

“Just giving my best to find the rhythm, which tonight was a great level of tennis. I feel like I am one step forward.”

And when she went a set and a break down against big-hitting Kanepi, it looked as though it could be another blow for last year’s runner-up.

But Halep bounced back instantly, Kanepi losing her nerve with a double fault on break point, then continued scrapping to eventually level the match by taking her fourth break point in the 10th game.

The final set stayed on serve at 3-2 in Halep’s favour – and then the Romanian struck.

Fighting back from 40-0 down to take Kanepi’s serve proved pivotal, the veteran visibly sapping as a result and winning only two more points as Halep moved into the next round.

“I knew that she’s hitting the ball very strong and it was going to take time to get ahead,” Halep added.

“I didn’t give up, which was really important. I think that’s why I could win the match.”

Seed Kasatkina beaten by world 192

Elsewhere, Daria Kasatkina became the first top-10 women’s seed to fall as she was thrashed 6-3 6-0 by Switzerland’s Timea Bacsinszky in 55 minutes.

Russian 10th seed Kasatkina coughed up nine double faults and hit just six winners against 192nd-ranked Bacsinszky.

However, fourth seed Naomi Osaka of Japan began her campaign in confident fashion with a 6-4 6-2 victory over Magda Linette.

And sixth seed Elina Svitolina made it safely through with a 6-1 6-2 victory over Viktorija Golubic.

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