Former champion Stan Wawrinka only decided on Saturday he would play the Australian Open as he prepares for a return from knee surgery.
The Swiss star has been sidelined since Wimbledon last year, having undergone surgery in August.
There were doubts the 2014 champion would be ready for the year's first grand slam, particularly after he withdrew from the Tie Break Tens exhibition event on Wednesday.
But Wawrinka, 32, confirmed on Saturday he had decided he would play the Australian Open.
"For me, I think the fact that I'm here and I'm going to play the first one, it's a big victory," he said.
"It's the best that I could have dreamed when I had the surgery, is to be here sitting in front of you and to say, 'OK, I'm going to play the first match'. That's something really good from my side, especially from the knee.
"The knee is getting way better. I still have a lot of work to do physically and also tennis-wise to be at my top level. I'm going to take the time I need for that. I know I need to get through those.
"I need to start somewhere anyway. I think here was a good start. It's a good place to start, to get pushed, to see also mentally how I'm going to react, how I'm going to feel when I'm going to be playing matches."
Wawrinka, the ninth seed, will face Ricardas Berankis in the opening round at Melbourne Park.
The three-time grand slam champion said he would need to be cautious on his return.
"It's the most important for me to be careful with the knee. That's why I waited until the last minute to decide if I was going to play or not," Wawrinka said.
"We decided with my team that the practice of today will make the decision if I'm ready or not. For me, most important was to make sure the knee doesn't risk anything.
"There's always a little risk, for sure, especially starting after six months in a match, you're going to get more tight, you're going to get nervous, you're not going to feel as comfortable in a match as in practice.
"But the knee is staying there, so that's the most important."
|BREAKING NEWS: Marchisio leaves Juventus|
|The Breakdown: A statistical look at round one of the Rugby Championship|
|Durham sign Bancroft for 2019|
|Wolfsburg to fine Hinds after training no-show|
|Rugby Championship 2018: Team-by-team guide|
|LaLiga 2018-19: Atletico Madrid ready for another title push|
|The big Friday Premier League quiz|
|Mets set franchise record in 20-run victory|
|Poyet threatens to quit after Bordeaux sell Laborde|
|Keys hits 55 winners en route to QFs, Halep claims rain-interrupted match|
|Djokovic-Dimitrov poised as rain wreaks havoc, Del Potro through|
|Tolisso: Pavard to Bayern? I don´t know|
|Ramos: Real Madrid will win again|
|Eagles QB Nick Foles suffers shoulder strain|
|Man City want to dominate English football, warns Walker|
|Golf behind Timberwolves´ draft mishap in 2009? Curry thinks so|
|Puig suspended, Hundley fined for starting Dodgers-Giants brawl|
|Snedeker leads Wyndham Championship with stunning 59|
|Yankees slugger Judge ´frustrated´ with wrist injury|
|Marlins pitcher Urena handed six-game ban for intentionally hitting Acuna|
|Pochettino expects ´toughest season´ yet at Tottenham|
|´You know you are not employing the Pope´ - Diamond has sympathy for Cipriani|
|Khedira still committed to Germany|
|Serena Williams reveals what shook her before worst loss of career|
|Burnley 1 Istanbul Basaksehir 0 (after extra time): Cork cracker sends Burnley through|
|Zenit hit eight in extraordinary Europa League fightback|
|Saints get back to winning ways at Wakefield|
|Giants medical team discovered tumour in Brittan Golden´s mouth|
|Maribor 0 Rangers 0: Gerrard´s men book play-off berth with calm clean sheet|
|Sassuolo reel in Marlon from Barcelona|
|Formula One ´very poor´, says Alonso after quitting|
|Brighton to host Southampton in EFL Cup second round|
|Tiger Woods´ caddie tried to pay heckler to leave Firestone|
|Sordet leads Nordea Masters, Olesen overcomes flight woes|
|Mourinho visits Istanbul Basaksehir before Burnley game|
|Iniesta hails ´worldwide sports legend´ Alonso|
|Onus on Ozil to rise above criticism, says ex-Arsenal star Wright|
|Lahm to head Euro 2024 if Germany wins bid|
|Tennis Australia ´extremely disappointed´ with Davis Cup revamp|
|Snedeker shoots 59 at Wyndham, after bogeying his first hole!|
|Lukaku hints at Belgium retirement after Euro 2020|
|Pellegrini rules out West Ham approach for Toure|
|Association of Spanish Footballers fumes at LaLiga´s US agreement|
|Seibold and Bennett hit out at media speculation|
|Cipriani ´truly sorry´ after pleading guilty to common assault|
|Man City´s Roberts makes Girona loan move|
|Davis Cup revamp passed by two-thirds majority vote|
|Pochettino ready to tackle Man City after Wembley NFL|
|Emery ends Arsenal goalkeeper debate with Cech assurance|
|Shastri: India happy to face Stokes in Nottingham|
|Etzebeth returns for Springboks, Pumas include Figallo|
|Two Serie A matches postponed after Genoa bridge collapse|
|Barrett tight-lipped over Manly future due to ´legal reasons´|
|N´Zonzi is better than Malcom - Monchi takes aim at Barca star|
|Sainz to replace Alonso at McLaren|
|Bayliss encourages Stokes to make public apology|
|Oates hat-trick boosts Broncos´ play-off ambitions|
|Emery needs four transfer windows to impact Arsenal – Wright|
|Spain´s LaLiga plans to play regular-season game in U.S.|
|´Dream come true´ for Robertson to earn Bledisloe Cup start|
|LaLiga match set for USA following groundbreaking Relevent deal|
|FIFA rankings: France number one, Croatia and England soar, Germany and Argentina plummet|
|Hansen hails ´big leader´ Whitelock ahead of 100th cap|
|Cipriani pleads guilty to common assault and resisting arrest|
|PSG snap up Kehrer from Schalke|
|Maitland-Niles facing two months out with broken leg|
|Walker backs City squad strength to overcome De Bruyne blow|
|Thomas & Froome skip Vuelta, named in Tour of Britain squad|
|Thurston rules out retirement U-turn|
|Pumas look to build on Jaguares progress in Rugby Championship|