Australian Open: Victorious Andy Murray vows to do his homework on Andrey Rublev

Murray shouted “wake up!” during one of many frustrating moments on Rod Laver Arena but a dozy display proved sufficient as the Scot sealed a 7-5 7-6 (7/5) 6-2 victory.

He will now face Russian teenager Andrey Rublev, the world No 152 who had earlier registered a surprise win over Yen-Hsun Lu.

Murray, walking out on court at just after 3pm local time, was not addressed as ‘Sir’ in the announcer’s introduction but that will have been of little concern to the top seed, who insisted in his post-match interview that “Andy is definitely fine”.

Instead, the Briton is keen to continue where he left off last season as he chases his first title in Melbourne, where he has reached the final five times but never been crowned champion.

The 29-year-old knows he will have to play far better than this if he is to lift the trophy, after a scruffy performance that included 27 unforced errors, three conceded breaks of serve and a tendency to adopt the kind of careful, cautious tennis that will run him into trouble against more proficient opponents.

“I don’t think it was the best match, to be honest,” said Murray.

“The conditions there were pretty different to what we’ve been practising on. The last week’s been pretty cool. A lot of days, it’s been overcast. The temperature of the court is much cooler.

“When it’s like that, the ball is bouncing a bit lower, (it’s) a bit easier to control the ball. I was a bit tentative because of that.

“And I didn’t serve that well either. So you end up having to work really hard on a lot of your service games when it’s like that. It just was tough.”

Marchenko, ranked 95th in the world and wearing his cap back to front, certainly offered a stern opening test, his exuberant shot-making and refusal to give in courting much support from an appreciative Australian crowd.

But baking hot conditions, with temperatures reaching 32 degrees Celsius, took their toll on the Ukrainian, along with Murray’s superior experience under pressure, which ultimately proved decisive.

Rublev will offer an altogether different proposition, coming in as one of the brightest talents on the tour and having previously played in only one grand slam main draw.

“I know a little bit about him,” added Murray said. “I’ve never hit with him or played against him but I’ve seen him play before and he goes for it. He doesn’t hold back. He hits a big ball”

Fellow Briton Dan Evans booked a second round showdown with Marin Cilic after he beat Argentina’s Facundo Bagnis.

Evans saved three set points against Bagnis before taking the opening set in a tie-break and he never looked back as the British No 3 sealed an impressive 7-6 (10/8) 6-3 6-1 victory.

He will now face Cilic, the seventh seed in Melbourne, who earlier on Monday had come from two sets down to beat Poland’s Jerzy Janowicz. Evans has never faced Cilic before in his career but the world No 51 has form for upsetting a big name.

He defeated Kei Nishikori in straight sets at the 2013 US Open and stretched Stan Wawrinka to five sets at Flushing Meadows last year. Wawrinka saved match point against Evans and went on to win the title.

Evans is also on an upward curve, after reaching his first ATP final last week in Sydney via a quarter-final victory over world No 8 Dominic Thiem.

Roger Federer admits his comeback was harder than he expected after the 17-time grand slam champion battled past Jurgen Melzer to reach the second round.

Federer was making his first competitive appearance in more than six months in Melbourne and the Swiss emerged unscathed, beating Melzer 7-5 3-6 6-2 6-2.

After sitting out the second half of 2016 to overcome injuries to his left knee and back, Federer showed signs of rust on Rod Laver Arena but he also improved as the match went on, giving away only four games and not a single break point in the final two sets.

“I think there were definitely some nerves there,” said Federer. “I think I struggled for a while to find that groove, that rhythm and everything.

“Then you remind yourself how many times has it not been easy in the first round. I’m happy I was made to work.”

Also through to round two is fellow Swiss Wawrinka but the No 4 seed was pushed all the way by Slovakian Martin Klizan in a five-set thriller.

“It was a tough one, for sure,” said Wawrinka said. “But I’m really happy to get through in five sets.

“It wasn’t my best tennis today but I was fighting, trying to stay in the game, fighting a lot.”

Wawrinka is due for a mouthwatering clash with Nick Kyrgios in the last 16 and the Australian also progressed after thrashing Portugal’s Gastao Elias 6-1 6-2 6-2.

Kyrgios’ compatriot Bernard Tomic was also in a defiant mood after he strolled past Brazilian Thomaz Bellucci 6-2 6-1 6-4.