Spike Spiegel (Cowboy Bebop) vs. Lara Croft (Tomb Raider)
No prep, but they're both in an enclosed, 15m by 40m space and aware of each other. Decent cover, both have access to their standard equipment. Minus the Swordfish. I wrote a little scenario below because I was bored, but you're free to ignore that. Or write your own little extension, if you want, that'd be pretty cool.
In the midst of exploring ancient ruins, and having just escaped a standard rolling boulder, the intrepid archeologist would rest behind a pillar in the new room. With the exit sealed behind her by the now-stuck boulder, the woman took a brief moment to catch her breath. Lara Croft, Tomb Raider extraordinaire, was after the famed MacGuffin, her bow and quiver on her back, pickaxe and pistol on her waste. After wiping the sweat from her brow, she stood, examining the room. 15 feet wide, 40 feet long, with 3 sets of 2 pillars that looked good for cover, despite varying states of decay. Looking towards the ceiling, she spotted a single rectangular hole in it, that seemed manually carved. She heard rustling alongside noticing a silhouette inside of it, looked away for just a brief moment to un-holster her gun, only to look back and see it empty. Her eyes drifted downward, seeing her new foe as she ducked behind a pillar.
"About time you showed up, have you gotten tired of stalking me?"
"Hey, you wouldn't believe how high your bounty is." The man, Spike Spiegel, a widely-renowned bounty hunter, slid behind the furthest pillar on the opposite side of the room, un-holstering his own pistol.
"Eight-digits?"
"Seven."
"Shame, I was hoping Trinity would put more up for me."