This famous Hollywood actor swapped his clean-cut look for a rugged beard on Sunday, as he brought his family along to a star-studded NBA game at the Crypto.com Arena in Los Angeles.
The 54-year-old joined a host of famous faces watching the Los Angeles Lakers take on the Portland Trail Blazers, including fellow movie star Don Cheadle.
He looked a far cry from his typical well-groomed red carpet appearances, as he relaxed on fun day out with his wife Luciana and their youngest daughters Gia, 16, and Stella, 14.
The Martian star sported a scruffy beard and black-rimmed glasses, while wearing a casual plaid flannel shirt and hiding his handsome face under a baseball cap.
Don, 60, looked effortlessly cool in a black bomber jacket and jeans, adding a cream baseball cap and a gold pendant necklace.
Other celebrities who were in attendance at the stadium to see the Lakers take victory over the Trail Blazers with a score of 107-98, were New Girl star Max Greenfield and Adele's sports agent fiancé Rich Paul.
Can you guess who it is? That's right, it's Matt Damon.
Matt's scruffier look appears to be for his upcoming Netflix film, RIP, which he is starring in and producing alongside his BFF Ben Affleck.
The crime thriller follows a group of Miami cops who discover a stash of millions in cash, leading to friction as outsiders learn about the huge seizure, making them question who they can rely on.
Matt and Ben were seen laughing while shooting scenes for the film in Los Angeles last month, and the Good Will Hunting duo are producing the movie via their Artists Equity production company, which they launched in November 2022.
Matt's outing with Luciana and their daughters comes after he revealed their family dynamic has changed since their 18-year-old daughter Isabella moved out and left for college.
The Oscar winner and his wife are the proud parents of daughters Isabella, Gia, and Stella, while he is also dad to daughter Alexia, 26, from a previous relationship.
Speaking to E! News about the family adjustment after Isabella left for college in September, Matt explained: 'We have a 26-year-old [Alexia], so we've been through this once before but it's still a major adjustment for us and her sisters.
'It's a different household with one less person there. So, it's a big adjustment.'
He previously got candid about what it means to be a girl dad during an appearance on SiriusXM show Radio Andy in August.
When asked what his best advice is on being a father to four girls, Matt admitted: 'Oh man I don't know. I wouldn't deign to give anybody advice other than I just try to listen and be helpful.
'I mean ultimately it's about building self-esteem. You know 99% of the decisions they make you're not gonna be there right?'
Host Andy Cohen then asked: 'What kind of dad are you when they bring a boy home and they say, "I'm dating this..."'
Matt replied: 'Oh I'm fine. I'm cool with that. You know what I mean?'
Andy probed further, asking if the famous Boston native doesn't 'turn all Boston' on his daughters' prospective partners.
But Matt assured: 'No, no, no. That's like an old trope that I think people, you know like to play up. You know dads like to joke about it amongst each other I think sometimes but no'.
The Talented Mr. Ripley star added that eldest daughter Alexia has an 'incredible' boyfriend, whom he and Luciana 'adore'.
He said: 'You know at least our [26-year-old] has you know, she's got this incredible boyfriend who Lucy and I just love. We adore the guy and to see that she's making those kinds of choices, really, it's as good as it gets.'
Matt and wife Luciana met in April 2003 in Miami at a bar she worked at, while he was in town working on comedy Stuck on You.
During an interview with Vogue Australia in 2018, Luciana spoke about the moment the couple first met, quipping: 'Matt's story is that he saw me across the room and there was a light on me. And I'm like, "Yeah it was a nightclub - there were lights everywhere!'
Luciana recalled that people were recognizing him and asking for pictures and autographs so Matt went behind the bar to hide.
She explained: 'It got kind of aggressive because people are drinking and stuff He came and hid behind the bar... [wanting to] just hang out back there and have a drink. He says, "Oh I saw you and I really wanted to talk to you."'
But she told him that if he wanted to stay behind the counter he had to help out, saying: 'He had trained as a bartender for a film years before so he started making drinks.
'And he made a ton of money in tips that night, because of course everyone wanted to go and see him. So it turned into a really fun night and then 15 years later here we are'.
Matt went on to pop the question to Luciana in September 2005 and they tied the knot just a few months later at the Manhattan Marriage Bureau on December 9.
