Nadal and Halep out on day of shocks in Melbourne

Nadal arrived at Melbourne Park with high hopes of arresting his recent grand slam decline only to depart, his optimism crushed, under a barrage of winners from fellow Spaniard Fernando Verdasco.

Shortly after a dejected Nadal walked off court having tasted his first opening round loss at the Australian Open, women's second seed Halep bid farewell while another high-profile casualty was seven-times major champion Venus Williams.

Andy Murray, the men's second seed, and 2014 champion Stan Wawrinka both impressed as the on-court action took centre stage after the allegations of matchfixing in the sport overshadowed Monday's programme.

Nadal appeared confused at how he had managed to blow a 2-0 lead in the final set to go down 7-6(6) 4-6 3-6 7-6(4) 6-2 to Verdasco in a four hour 41 minute battle that had echoes of their marathon 2009 semi-final but with a reversed result.

The fifth seed, who failed to win a grand slam title last year for the first time in a decade, lost the last six games as world number 45 Verdasco unleashed a series of explosive forehands to take his place in the second round.

"He was playing amazing in the last set. If you decide everything in one set, the opponent is ready to hit all the balls at hundred percent, then you are in trouble," the 2009 champion told reporters.

"The real thing is I was not enough aggressive with my forehand during the whole match. I didn't feel it. I tried. I fought. I was ready to do it, and I didn't. I am sad for that."

Halep gave similar reasons for her 6-4 6-3 defeat at the hands of Chinese qualifier Zhang Shuai, who was ranked 131 places below the Romanian in the rankings going into their contest over on Margaret Court Arena.

"I think it wasn't my good day but I give her a lot of credit as she played without fear and hit every ball," Halep, who has been struggling with an Achilles injury, told reporters.

"She beat me. It's tough but it's only one day, only one match and I have many matches ahead of me."

TEARFUL ZHANG

Zhang burst into tears after winning her first grand slam singles match at the 15th attempt, later revealing that she had considered quitting the sport.

"I wanted try one more time, only one more time, yeah," she said. "If Australia Open not good, maybe I finish tennis."

Like Nadal, veteran Williams had been hoping to carry a resurgence in form from 2015 into the New Year but she was similarly disappointed after a 6-4 6-2 defeat at the hands of British number one Johanna Konta.

The 35-year-old eighth seeded American faces a likely fine from organisers after holding a post-match news conference.

Seventh seed Angelique Kerber had to save a match point to stave off a fourth shock, rallying to beat Japan's Misaki Doi 6-7(4) 7-6(6) 6-3, while third seed Garbine Muguruza beat Estonian Anett Kontaveit 6-0 6-4.

Victoria Azarenka, twice an Australian Open champion, underlined her return to form and fitness, thrashing Belgium's Alison Van Uytvanck 6-0 6-0 in the final match of the day.

Murray's earlier encounter with teenager Alexander Zverev was delayed in the second game when the German suffered a nosebleed but the former Wimbledon champion's path to the second round otherwise ran smoothly.

The British four-times runner-up won 6-1 6-2 6-3 on Hisense Arena while Wawrinka, his possible semi-final foe and the only man to have broken Novak Djokovic's grip on the Melbourne Park title in the last five years, had an even shorter day, going through when Russian Dmitry Tursunov retired hurt after the second set of their contest.

Former world number one Lleyton Hewitt delighted the Rod Laver Arena crowd by extending his career for at least another two days with a 7-6(5) 6-2 6-4 victory over fellow Australian James Duckworth.

Hewitt, who is retiring after his 20th Australian Open, sent his compatriots into a frenzy when he wrapped up the match with a trademark lob to set up a clash with eighth seed David Ferrer.

"This is what I'm going to miss the most, the buzz from the crowd," he said.