Fourth seed Stan Wawrinka survived a huge scare to reach round two of the Australian Open on Monday, as a number of leading seeds made unconvincing starts to their respective campaigns.
Wawrinka - the champion at Melbourne Park in 2014 - was taken to five sets by Martin Klizan and trailed by a break in the decider before eventually prevailing 4-6 6-4 7-5 4-6 6-4.
Top seed Andy Murray, a five-time Australian Open runner-up, was a straight-sets winner over Ilya Marchenko but looked well below his brilliant best, while Roger Federer overcame a mid-match wobble to beat Jurgen Melzer in four.
Along with Wawrinka, Kei Nishikori and Marin Cilic were taken to five sets, but the big guns ultimately all prevailed - with 16th seed Lucas Pouille the highest-profile casualty of the opening day.
STAN COMES BACK FROM THE BRINK
Wawrinka has never lost in the first round at Melbourne Park, but that record looked set to end as Klizan broke for a 4-3 lead in set five before getting to 40-15 on serve.
The Slovakian could not make it over the winning line on Margaret Court Arena, however, and was also dealt a painful blow as a Wawrinka smash caught him in the most painful of places.
New balls, please?
CILIC REPEATS JANOWICZ COMEBACK
Marin Cilic was another big name who came through a testing time on Monday, losing the first two sets to Jerzy Janowicz - a player without a top-level win since 2015 following significant injury trouble in recent times.
However, Janowicz had failed to capitalise on a two-set lead in his last meeting with Cilic, at the 2014 Davis Cup, and history was repeated as the seventh seed hit back to win 4-6 4-6 6-2 6-2 6-3.
Nishikori had to work hard for his 5-7 6-1 6-4 6-7 [6-8] 6-2 triumph over Andrey Kuznetsov. In contrast, Nishikori's next opponent, Jeremy Chardy, was gifted an easy passage to round two when Nicolas Almagro retired through injury after just four games.
Pouille, meanwhile, lost in four sets to the unheralded Alexander Bublik and fellow seeds Pablo Cuevas and Albert Ramos-Vinolas also made early exits.
FEDERER JOKES OVER GQ AWARD
Federer cut a relaxed figure after his win over Melzer, which was largely routine barring an unexpected streak of five successive lost games that saw the 17-time grand slam champion throw away the second set.
In an on-court interview, Federer - who was troubled by injuries in 2016 and missed two grand slams - was asked about being named as GQ magazine's Most Stylish Man of the Year in 2016.
"It's the most important award of the year for me," joked the 35-year-old. "At least I won something last year."
60 STRAIGHT SLAMS FOR LOPEZ
Feliciano Lopez, the 28th seed in Melbourne, will reach an impressive milestone on Tuesday when he makes his 60th successive appearance in a grand slam singles draw.
Only Federer, who played in 65 consecutive slams before missing last year's French Open through injury, has enjoyed a longer run of outings at the highest level.
Lopez takes on Fabio Fognini in round one and tweeted on Monday: "It's a pleasure to be able to celebrate my 60th consecutive Grand Slam at the @AustralianOpen. I feel proud after so many years!"