It would be grossly unfair to label the start of the female champion's defence as a curtain-raiser. But, undoubtedly, most people inside Laver wanted that match out of the way rather quickly. 

Because next is the biggie. R Fed's return...

Stan Wawrinka looks to be closing in on a place in the second round after a two-hour match against Slovakia's Martin Klizan. 

He's currently 2-1 up after a shaky start.

Leon Smith
Great Britain Davis Cup captain on BBC Radio 5 live Sports Extra

The most important thing for Angelique Kerber is getting the win and finding a way through. She started to play better in third set but knows she will have to play better. There were a lot of nerves and tension.

Angelique Kerber: "I have to say I'm really happy to be back here. Everything started here for me when I won my first Grand Slam here. Thank you all for your support.

"I won the match and that's what counts. The first round is always tough. I'm so happy to be in the second round."

Image source, EPA

Angelique Kerber takes a deep breath, composing herself ahead of what she hopes is her final ball toss. She ramps up the pressure, smacking a wonderful forehand down the line for 30-0, then seeing Tsurenko thump a forehand of her own well wide.

Match point....

Has Lesia Tsurenko's race been run? One would assume so. She gifts a couple of break points to Angelique Kerber with an unforced error, and although she survives one, there's no stopping Kerber at the next opportunity.

Tsurenko grimaces as a backhand wanders left of the court, shrieking as it lands in the tramlines.

A double break for the reigning champion...

Angelique Kerber is playing with much more authority now - although there are still a few nerves there. An edgy double fault gives Lesia Tsurenko - whose movement is also causing Kerber bother - a chance at 40-30. But the German redeems herself in the next point, pulling Tsurenko left, then thronking a brutal backhand down the opposite flank.

Leon Smith
Great Britain Davis Cup captain on Radio 5 live sports extra

That's a big game. That is going to make Kerber feel a hell of a lot better.

She's got it! These two players are slugging away from the baseline, trying to lure each other into an error. Who is going to fold first? It's Lesia Tsurenko.

Angelique Kerber keeps returning everything the Ukrainian can throw at her, before her 51st-ranked opponent tugs a forehand into the tramlines. 

Just when you think Angelique Kerber is finding her rhythm, she ends up missing a beat. The German top seed slaps her strings in frustration when she drills a forehand into the net chord for 30-15, before sticking her foot back down on the pedal.

A rogue backhand after a long rally hauls her back to 30-30, before Tsurenko has to face a break point when she goes long with a forehand...

Clever, crafty work from Lesia Tsurenko, getting plenty of top spin on a forehand to beat Kerber's outstretched racket. Kerber's rattled, a double fault leading to a look of annoyance, but that is stunning from Tsurenko. A delicate, perfectly placed backhand beats Kerber, but she stretches and thuds the ball hard to bring it to deuce. Two forehand slams means she holds.

Who will blink first? Kerber yells as she unleashes a forehand that beats a darting Tsurenko, but her opponent's well-timed backhand catches her off guard. Kerber challenges an out call but she doesn't look confident, sitting down before the technology confirms that it was indeed out, and Tsurenko holds her serve.

Kerber takes a big puff of air as she lines up her serve, and she's gifted a few points as Tsurenko misjudges her forehand. Kerber holds her serve and pumps her fists as the crowd applauds.

No such problems for Nick Kyrgios. No outbursts, no slunking of the shoulders, just an excellent win. 

The 14th seed drops only five games in his opener against Portuguese lad Gastao Elias, who is ranked 81st in the world.

L'enfant terrible wins 6-1 6-2 6-2 in 84 minutes. Next? Italy's Andreas Seppi.

Quite a strange atmosphere in Laver. Most of the crowd, I think it is fair to say, want this match done and dusted. They're here for the main man - Roger Federer. However, they might end up seeing an almighty shock before he appears...

Into a decider! Finally, finally, Lesia Tsurenko pushes herself over the line. The Ukrainian takes her fifth set point, pushing Angelique Kerber back onto the baseline, the top seed slapping a weak backhand into the net.

Tsurenko kept plugging away, Kerber unable to hold her off. Not all plain sailing for the reigning champion...

Again, Lesia Tsurenko can't convert. Her third attempt at taking this to a decider flying an inch or two over the baseline. But Angelique Kerber is just not clicking. Tsurenko racks up a fourth set point - and it is gone as quickly as it arrives. A wicked forehand is whipped down the line by Kerber.

Oh dear. The usually-clinical Angelique Kerber is trying shots that she wouldn't try. Serious pressure. A clunky forehand from the back right corner is gobbled up by the tape... set point number three.

One set point goes begging for Lesia Tsurenko - but it isn't long before she gets another chance. This time the Ukrainian, ranked 50 places below the top seed, goes long as Kerber puffs out her cheeks in relief...