Lewis Hamilton and Sebastian Vettel will both be hoping to become just the third man to win a fifth Formula One world championship in 2018.
Hamilton prevailed in a battle with Vettel last season as Ferrari finally looked capable of providing a winning driver for the first time since Kimi Raikkonen's triumph in 2007.
The Briton's fourth title came nine years after his first, with his German rival claiming all of his in succession during a dominant stint with Red Bull.
A place in motorsport immortality alongside Michael Schumacher and Juan Manuel Fangio awaits, but who is best placed to achieve it this year?
The case for Hamilton
Mercedes have been untouchable at the pinnacle of F1 for the past four seasons, with Hamilton only beaten to the title by team-mate Nico Rosberg during that period.
It is difficult to envisage the German team's stranglehold over the sport loosening as they came out of pre-season testing with the best race simulations, although those stints were done on only one tyre compound.
Hamilton trailed Vettel in the early stages of the previous campaign but his single-mindedness and determination to prove himself as one of the elite saw him dig in and, following the mid-season break, he overturned a 14-point deficit to the German with a run of six wins in eight races.
It does not appear winning the championship for a fourth time has taken away any of his desire to make himself the man to beat this year.
"I am on the same level as every driver here, but I want to prove that I am above them and that means I have got to work harder than I have ever worked before," said Hamilton.
It will certainly take something special to stop him from proving that point.
The case for Vettel
Vettel heads into this season as the fastest man across both testing sessions in Barcelona.
The German finally got the chance to challenge for a title in a Ferrari last year, with a run of six successive podiums to start the campaign laying the foundations.
His tilt unravelled in the second half of the season; Vettel was caught in a crash involving Raikkonen and Max Verstappen in Singapore and suffered an engine problem in Japan, and Hamilton took full advantage by winning both races.
If Ferrari can avoid reliability issues across an entire season and the 30-year-old does not have the misfortune of being wiped out of a grand prix, there is every possibility he can push Hamilton all the way.
Should Vettel manage to at least stick close to the Mercedes star, he can force his rival into taking greater risks from which he can deliver a punishing blow.
His performance in Barcelona suggests Ferrari have the speed to cause some real problems this year, but it will take a flawless campaign from him and the team to dethrone Hamilton and Mercedes.
|Yankees interested in Machado, not Harper - Cashman|
|Warriors´ Curry believes moon landing was faked|
|76ers star Butler suffers strained groin|
|Brady: Patriots still have a lot of football to play|
|´No one died´ - Belichick´s message to Patriots after stunning loss|
|Silva lauds Digne after stunning free-kick|
|Aduriz joins Messi, Ramos in LaLiga history books|
|We have a plan - Ravens coach Harbaugh prepared for Flacco return|
|´It´s difficult to accept´ - Gracia calls for introduction of VAR|
|LaLiga press on with overseas match plan despite Barcelona withdrawal|
|PSG open Coupe de France defence at fifth-tier Pontivy|
|Hazard backs Sterling as Neville reveals England star´s Euro 2016 concerns|
|Everton 2 Watford 2: Digne salvages draw with 96th-minute free-kick|
|Barcelona could ´steal´ Kane, says Pochettino|
|Oakland Raiders fire general manager McKenzie|
|Struggling Villarreal appoint Garcia Plaza as Calleja successor|
|Warriors assign Cousins to G League team|
|Barcelona pull out of plan to play LaLiga game in Miami|
|Pochettino to keep an eye on Inter when Spurs face Barcelona|
|Pochettino confirms Walker-Peters set to start against Barcelona|
|Denver Nuggets add free agent Young|
|Topping Group A no magic wand for an easy knockout draw, says Simeone|
|The cake has been made, now we need the cherry - Ancelotti targets repeat at Anfield|
|Lloris braced to face ´one of the best in history´ in Messi|
|Tuchel expects Neymar to face Red Star|
|Foden signs Manchester City deal to 2024|
|It happened to me! - Valverde laughs off Dembele timekeeping|
|´Projecting´ an Argentina return? Messi met with AFA president and Scaloni|
|Erasmus expects to leave head coach role after World Cup|
|Chelsea issue suspensions pending investigation into Sterling incident|
|Kane is extraordinary – Valverde hails reported Barcelona target|
|Man behind Naomi Osaka´s rise wins WTA Coach of the Year|
|England name unchanged Test squad as Willey returns for West Indies ODIs|
|Spalletti: No issue with Icardi watching Superclasico in Madrid|
|Klopp confirms 2013 talks with ´chatty´ Napoli president De Laurentiis|
|Sri Lanka spinner Dananjaya suspended due to illegal action|
|His reaction was just brilliant – Klopp praises Sterling for response to abuse|
|Gomez renewal a ´smart decision´ for both parties – Klopp|
|Magnificent Molinari named European Golfer of the Year|
|Barcelona best option for Frenkie de Jong, insists midfielder´s father|
|Gronkowski on Miami Miracle: ´Got to make that tackle´|
|Tottenham youngster Walker-Peters signs on until 2023|
|Juventus ´more of a family´ than Real Madrid - Ronaldo|
|Kingsley Coman contemplates retirement if injury nightmare continues|
|McVay ´sick´ over offensive failings as Rams coach takes blame for loss|
|Calleja axed as Villarreal coach|
|Kenyan Drake on Miami Miracle: I couldn´t let Gronk tackle me!|
|Ronaldo: I deserved Ballon d´Or, the numbers don´t lie|
|Rugby Australia to make Cheika decision this month|
|England defender Gomez signs new Liverpool deal|
|Ronaldo wants to see Messi follow him to Italy|
|Neymar happy to play in any position for PSG - Draxler|
|Paine insists he is ´fine´ after taking blow to finger|
|Ponzio: River players will be ´idolised´ for Libertadores success|
|Champions League permutations: How Inter, PSG and Liverpool can progress|
|Kohli: India were better and deserved to win|
|Bears shut down Goff, Rams|
|India survive dramatic finish against Australia|
|Klopp calls for electric Anfield atmosphere against Napoli|
|Saints clinch back-to-back NFC South titles, Bears trump Rams|
|Bucks improve to 2-0 against Raptors with win in Toronto|
|Black Caps include Patel for Sri Lanka Tests|
|Maidana: River want Real Madrid clash|
|Cowboys top Eagles in OT behind stellar Cooper display|
|AC Milan evaluating Fabregas signing – Leonardo|
|WATCH: Steelers´ chance at game-tying field goal slips away|
|Hayne will plead not guilty to charges, says lawyer|
|Boca boss Schelotto: The only thing I feel is sadness|
|Cardinals´ Fitzgerald makes NFL history with most receptions for one team|
|River Plate´s Copa Libertadores star Gonzalo Martinez confirms January departure|