(Sports) Roundup: Nadal battles through "toughest ever victory" in Australian Open

World No.3 Rafael Nadal overcame a mighty scare from American qualifier Tim Smyczek to secure what he described as his "toughest ever victory" at the Australian Open on Wednesday evening.

Nadal battled through stomach cramps and dizziness in a five- set thriller, finally seeing off the threat of Smyczek after more than four hours to win 6-2, 3-6, 6-7 (2-7), 6-3, 7-5.

On the women's side, No.3 seed Simona Halep enjoyed a more routine passage into the next stage of the competition, defeating Australian hopeful Jarmila Gajdosova in straight sets.

However, there was some luck for the home favorites, with both Nick Kyrgios and Bernard Tomic defeating seeded opponents to ensure Australia would have its first player, other than Lleyton Hewitt, in the final 16 of the tournament for the first time in 11 years.

On center court in the evening's showpiece event, even an underdone Nadal was expected to ease through his second-round clash with world No.112 Smyczek.

However, the plucky American had other ideas. Despite Nadal taking the first set comfortably, Smyczek fought back and leveled the match, before claiming the third set in a tiebreak.

As Nadal called for an injury timeout, complaining of a stomach cramp, it seemed as though the American had the upper hand. But back fought Nadal to send the match to a deciding set, which he claimed after breaking at 6-5.

Gallantly, Smyczek saved three match points, before Nadal's quality eventually shaded the contest.

But, despite the victory, Nadal said he didn't believe he had the ability to fight back from his illness.

"I felt very tired and after the first set, my body felt very bad," Nadal told reporters after his victory, "I was very tired and I was sweating like crazy."

"When I was serving in the third (set), I almost threw up. It was a terrible feeling and I suffered too much on court. It was not fun today.

"In terms of feeling bad (physically), yes it was my toughest ever victory."

On the women's side, Halep barely raised a sweat as she saw off the challenge of Gajdosova 6-2, 6-2.

The highly rated Romanian was unstoppable from the baseline and broke her opponent on four occasions to seal a comfortable win.

Earlier, in the men's draw, Australian teenager Kyrgios continued the host nation's giant-killing trend, following in Thanasi Kokkinakis's footsteps from the first round by defeating world No.23 Ivo Karlovic.

Kyrgios was made to battle against Karlovic's big serve, but profited from two double-faults midway through the fourth set to break the Croatian and clinch a hard fought 7-6 (7-4), 6-4, 5-7, 6- 4 victory.

However, 18-year-old Kokkinakis's run ended at the hands of a fellow Australian, Sam Groth.

In a five-set epic, Kokkinakis won just five points off his own serve in the final set as fatigue set in, with Groth advancing to the third round with a 3-6, 6-3, 7-5, 3-6, 6-1 win.

Groth will now play fellow Australian Tomic in the third round, after he defeated world No.22 Philip Kohlschreiber in four sets.

The often outspoken Tomic held his nerve in two consecutive tiebreaks to win 6-7 (5-7), 6-4, 7-6 (8-6), 7-6 (7-5).

He described the third set tiebreak, in which he stormed from 3- 6 down to win five straight points and claim the set, as the defining moment in the match.

"Tennis is a funny sport sometimes, you can be up and winning and then, all of a sudden, it can change with one shot," Tomic said after the match.

"I was losing and had three set points against, but I just strived to somehow win two points on my serve and then I thought ' go for it' and hit that shot.

"I can't complain, I played very well, he was playing very well, it was good tennis and I served very well and that's what helped me a lot throughout this match."

Meanwhile, in the women's draw, No.7 seed Eugenie Bouchard swept aside Kiki Bertens to advance to the third round with a comfortable 6-0, 6-3 victory. Endi