File under: The gang that Couldn't Shoot Straight.

The bottle that split open the head of Chris Brown's GIGANTIC bodyguard Wednesday night was thrown by a member of Team Breezy ... TMZ has learned.

Multiple witnesses say ... Brown's hired muscle, Big Pat, was standing  in front of Chris when the bottles started flying. We're told Big Pat turned towards Chris ... when someone in Brown's own entourage fired a bottle intended for Drake's party, but missed ... bad.

Instead, the bottle connected with Big Pat's face at extremely close range ... and opened a giant bloody gash on his forehead.  Pat ended up suffering the worst injuries of anyone in the club -- ironically from his own posse.

Pat received emergency medical treatment for the wound -- but he appeared fine the next day.

TMZ has obtained a photo of Chris Brown inside a NYC nightclub, taken seconds before he got clocked with a champagne bottle in a brawl with Drake's posse -- and he looks totally oblivious to the violence about to erupt.

In the photo, Chris is shirtless and holding a bottle of Ace of Spades champagne … surrounded by fans, friends -- and his bodyguard, Big Pat, who ended up hospitalized with a massive gash to his forehead after the brawl broke out in W.i.P. Nightclub early Thursday.

According to several eyewitnesses, Drake and Chris had been jawing at each other leading up to the brawl -- still, Chris doesn't look the least bit concerned in the photo.

We also obtained pics of Drake -- taken minutes earlier -- and rapper Juelz Santana is already standing next to him. We're told Juelz, Meek Mill, and Trav B all stepped up for Drake … and eventually tussled with Chris and his crew.

As TMZ first reported, NYPD officers have spoken to Chris, Drake and their attorneys. Neither has been named a suspect in the beatdown.

Last night, Rihanna hit the club scene in NYC -- but when she was asked about the Drake vs. Chris Brown brawl ... she bobbed and weaved like a prize fighter.

More bloody heads -- Chris Brown's bodyguard Big Pat was also hospitalized last night with a GIANT GASH on his forehead, following the massive bottle-hurling brawl at W.i.P nightclub in NYC.

The photo surfaced on Twitter earlier today -- showing Big Pat in a hospital gurney, blood gushing all over the place. It's unclear exactly how BP got hurt or who's responsible for the damage.

Thankfully, looks like the guy's okay -- he showed up moments ago outside Chris' NYC hotel, badly scabbed up ... but walking nonetheless.