Hollywood heavyweights Kevin Hart and Dwayne Johnson make a charismatic pairing on and off-screen. So long as the praise is balanced with plenty of banter, of course, they tell Susan Griffin.
Dwayne Johnson and Kevin Hart are two of the most powerful players in Hollywood right now, so it's no surprise to hear they enjoy a healthy amount of competition.
"Supportive but always competitive" is how Johnson - a colossal 6ft 4in presence in jeans and a blue T-shirt, straining over tattooed biceps - describes their relationship.
"With us, it's a daily race. Who's getting up first, who's training longer, who's stronger, who's better, who's quicker?"
It seems they've taken great enjoyment in winding each other up while promoting their new movie, Central Intelligence, jesting with photos and videos on social media.
At the last count, Johnson has over 10 million Twitter and 56 million Instagram followers, while Hart can boast 30 million and 37 million devotees respectively. With the jury out on who's more influential, one particular text exchange hit Johnson hard.
"We were going back and forth and - bang, he ends it with his emoji," says the former wrestler, sporting a shaved head and a smattering of dark grey stubble.
"He's got a Kevin Hart emoji! I'm like, 'Jesus Christ, he beat me to getting my own'," he adds, grinning.
Hart announced the imminent arrival of the 'Kevmoji' during a video filmed on board a private jet.
It might sound like the diminutive funny man was showing off, but he underplayed things by catching sight of some grey hair and joking he's morphing into Morgan Freeman.
Today, there's no sign of silver hair as Hart - who stands a foot shorter than Johnson but also looks athletic, in jeans and a white T-shirt - finds great delight in his co-star's admission.
Their rapport is evident, so news that they're teaming up again later in the year, for a remake of Robin Williams movie Jumanji, comes as little surprise.
But first it's all about Central Intelligence, an action-comedy which centres on Bob (Johnson), once a bullied schoolboy who's grown up to be a lethal CIA agent (with a penchant for unicorns and bumbags).
Returning home for his 20-year high school reunion, he contacts Calvin (Hart), the former 'big man on campus', now a straight-laced accountant missing his glory days, who realises all too late that Bob's managed to implicate him in the world of espionage.
"It's about a lean and mean killing machine, teaming up with a nine-to-five 'Everyday Joe' to unravel this plot," explains Hart (36). "Calvin's doing stuff he's never seen or done before, with barely any time to react. He's truly a fish out of water."
For both men, the idea of playing against type was part of the appeal.
"That was the attractive part about this film," states Philadelphia-born Hart, who has two children from his former marriage (he's reportedly due to tie the knot again this summer, with model fiancee Eniko Parrish).
"I laughed at DJ throughout this film. Yes, you have moments where you're laughing at my character, but for the most part, I'm the straight guy and I'm in this mess."
"You bring the heart to it," adds Johnson, (44), who was born in California but moved around a lot growing up, as the son of famous wrestler Rocky.
"It was also one of those things where we felt like if we were going to work together, let's deliver something different for the audience and not what they'd expect."
Directed and co-written by Rawson Marshall Thurber, who brought us We're The Millers and Dodgeball, the overriding theme of the movie is how our formative experiences at school can often affect us as adults.
"Bob is one of the world's most deadly individuals, a badass who can take you out just like that, kill you 19 different ways and you'd better cancel Christmas," says Johnson, who recently became a father for a second time (he and girlfriend Lauren Hashian welcomed daughter Jasmine in December).
"That's one side of him. The other side is this guy who in some ways, never really developed past that day when he ended up butt-naked on the gym floor (thanks to bullies, as illustrated in the film's opening sequence), so he looks at things in a wide-eyed, childlike way."
As for Calvin, his initial reunion with Bob "feels like another foot on his back".
"Here's a guy who has achieved so much and it makes Calvin reflect on the things he hasn't done himself," explains Hart. "But Calvin's life begins to change the night he meets Bob for a drink. An innocent evening turns into mayhem, but in a way, it's nice to be reminded of what he's capable of, and it's like that cloud over him starts to remove itself."
Their vast height difference is an ongoing visual punchline, but Thurber notes the actors are "cut from the same cloth, and so much alike in their generosity and the way they take the work seriously, but don't take themselves so seriously".
They've both used their distinctive physical attributes to their advantage, Johnson in the likes of The Scorpion King, Hercules and the Fast and Furious franchise, and Hart in the likes of Get Hard opposite the gangly Will Ferrell and mega-successful comedy I'm A Grown Little Man - but it's not been an effortless journey for either of them.
"I've changed every role that's ever been offered to me. Any role I went into in the past was written for a tall, white guy," comments Hart - laughing but not joking. "Scripts are there for years. Goodness, I can go back to so many films I've done and they go, 'Oh Kevin will be good for this now', and then you read the (initial) description and it's, 'bald guy, 47, businessman'."
But money talks, and box office appeal equates to greater creative freedom.
"That's the beauty of Hollywood and success," observes Johnson, who recently finished filming on the big-screen outing of Nineties favourite Baywatch, a "racy, raunchy, edgy" movie which he also co-produced.
"We're both workaholics," adds Hart, "and we understand we're blessed and fortunate to be in this position, and don't take anything for granted."