ANDY MURRAY felt the potency of his serve was the difference as he moved into the third round of the Australian Open with a straight-sets victory over Illya Marchenko.
The British No 1 was not at his fluent best but always seemed to wriggle out of trouble, helped appreciably by 16 aces, as he downed the Ukrainian 6-1 6-3 6-3 in a little under two hours.
The serve has not always been the strongest facet of Murray's game but with Marchenko matching him off the ground, it came to the fore.
"I got a lot of free points on the first serve, which is important because from pretty much the first game he was swinging quite big on first-serve returns and the second serve," said Murray.
"I think once it got close, he started to miss more, because I didn't feel like I hit my second serve badly. It was important to get free points off the serve."
Marchenko, ranked 79 in the world, promised "trouble" for the British No 1 but it never really materialised as Murray won through to a last-32 meeting with Spaniard Guillermo Garcia-Lopez.
Murray sprinted through the first set in front of a raucous sell-out crowd on Margaret Court Arena, taking it in just 29 minutes thanks to two breaks.
Marchenko rallied at the start of the second, two booming forehands and a crunching backhand giving him three break points – his first of the match.
The world No 5 saved two but not the third as he netted a routine backhand to give the Ukrainian a 2-0 lead. Marchenko promptly undid all his hard work, however, a horrible shank on break point getting the set back on serve.
Murray again looked vulnerable at 2-1 down but two big first serves got him out of trouble.
Both players were becoming irritated by the line-calling and with the court not having Hawk-Eye there was no method of appeal.
Marchenko got a particularly bad call in the first point of the fifth game. He slapped a forehand from close to the net on to the line only for the umpire to call it out, prompting the incensed Ukrainian to tell the official to "open your eyes".
The incident seemed to affect the 23-year-old from Dneprodzerzhinsk and he lost his focus, losing his serve after dumping a weak forehand into the net.
A further break saw the Scot clinch a two-set lead.
Murray was starting to warm to the task and despite Marchenko's best efforts, he made the breakthrough in game six to establish a 4-2 lead.
He almost clinched the match with Marchenko serving at 5-3 down, one stunning forehand pass on the run bringing the crowd to its feet.
But he made no mistake in the next game as Marchenko failed to control a forehand.
Rafael Nadal's dream of completing the 'Rafa Slam' remain alive.
Nadal, who is bidding to become the first man since Rod Laver in 1969 to hold all four grand slam titles simultaneously, was far too strong for Ryan Sweeting as he moved into the last 32 along with fourth seed Robin Soderling.
Spaniard Nadal, who was leading Marcos Daniel 6-0 5-0 in round one before the Brazilian retired, was pushed slightly harder by American Sweeting but the outcome was still a formality as the world No 1 cruised home 6-2 6-1 6-1 in one hour and 42 minutes.
He will next meet rising Australian star Bernard Tomic, who stunned 31st seed Feliciano Lopez 7-6 (7/4) 7-6 (7/3) 6-3.
Nadal said of the 18-year-old: "He's very young but he has the potential to be in the top positions in the future. I will have to play well if I want to win."
Soderling beat Luxembourg's Gilles Muller 6-3 7-6 (7/1) 6-1 to reach the third round at the event for the first time.
Andy Murray's brother Jamie and partner Xavier Malisse enjoyed a fine first-round mixed doubles win, putting out ninth seeds Wesley Moodie and Dick Norman.
Murray and Belgian Malisse were made to work hard in the first set by the South African pair, but then cruised through the second to win 6-4 6-0.