Serbian world No.1 Novak Djokovic overcame the effects of jet lag to power past Italian Andreas Seppi 6-3 6-4 in Monday’s Hopman Cup encounter in Perth.

Djokovic only arrived in Perth late on Sunday afternoon after winning an exhibition tournament in Abu Dhabi.

But the lengthy flight over and the four-hour time difference didn’t seem to faze Djokovic, who looked sprightly in the 84-minute contest played under a closed roof at Perth Arena.

Djokovic’s win gave top-ranked Serbia an unassailable 2-0 lead in the tie after Ana Ivanovic defeated Francesca Schiavone 6-0 6-4 earlier in the day.

“I arrived quite late last night and didn’t get a lot of sleep,” Djokovic said.

“I felt like I was dream-walking this morning.

“But as the match went on, I was managing to get my rhythm.

“It took twice as much effort.”

With the temperature in Perth nudging past 40 degrees during Djokovic’s match, the arena’s roof was closed during the men’s singles rubber.

But the women weren’t as lucky, with Ivanovic and Schiavone forced to slug it out in 36-degree heat during their contest.

Ivanovic thrived under the hot conditions, breaking Schiavone three times in the opening set and unleashing a flurry of winners in the 70-minute contest.

“That’s the style of game I always had and I always was an aggressive player,” Ivanovic said.

“I try to dominate and step in and take risks sometimes.

“It doesn’t always go your way, but that’s the way I have to play and it worked well for me today and it gives me confidence.

“I got a little bit of momentum going.

“I felt like I played well so I got a few fist pumps going.”

Meanwhile, world No.112 Tatjana Malek has been locked in as a replacement for Germany’s Andrea Petkovic, who was forced to pull out of the mixed teams’ event with a knee injury.