This would be a great fight. I'm leaning towards Captain America though. Here's why...
IIRC, The Lizard was a scientist who transformed into some sort of half-human/half-lizard who was pretty darn strong, fast, durable and w/ rapid healing.(e.g. plowing through cars in heavy traffic, tanking a hail of gunfire from a SWAT team, scaling buildings really fast, healing limbs etc) He also had great reflexes that matched Spider-Man. Most of the time The Lizard was doin' the butt kickin'. He also possesses high intellect/senses. (retaining his intelligence in Lizard form, sniffing out Gwen Stacy etc.) Quite a formidable foe. Although he showed almost zero fighting technique other than swiping, grappling and tail attacks. Really what any normal Joe would do if they were turned into a big lizard although not at all to take away from his other attributes.
For a human, Captain America has shown incredible feats of strength (i.g. holding a motorcycle w/ 3 women over his head, punching through the pressurized cockpit of a submarine, punching a punching bag so hard he sent it flying yards away, bending a metal railing with ease etc.) He's also shown great speed/agility (e.g. running at about 26 mph, almost catching up to a Hydra bomber about to take off, leaping very far distances, evading Chitauri energy weapons etc) Another notable attribute is his surprising durability (Surviving a plane crash in the arctic/suspended animation for 70 years, withstanding blows from Loki, walking away from smashing on top of a car, tanking a Chitauri energy blast, skydiving from a Quinjet w/o a parachute/pencil into the Indian Ocean, lifting a metal beam that weighed at least a ton after getting shot multiple times, eating punches from Winter Soldier's bionic arm, etc.) When armed with his indestructible shield, one of his greatest attributes is his fighting prowess/combat awareness.(e.g. winning WWII, reflecting Loki's staff blast, playing handball with a grenade, kicking the crap out of cyborg aliens, taking out a fighter jet with a shield, clearing a Hydra-carrier with a shield etc.) Last but not least, his most important attribute is his heroism. His fighting spirit to overcome odds and lead others to victory. (e.g. his flag stunt, jumping on a grenade, winning WWII, leading the Avengers, going on the run to reveal a global threat, willing to sacrifice himself to save millions of innocents, convincing a brain wasted Winter Soldier that he's his long, lost friend etc.) Although, in the Lizard's favor Cap's leadership does nothing in this fight since its a one-on-one.
Now I know I this reply is verbose but I had to make a clear argument in Captain America's favor. The Lizard has displayed astonishing feats no doubt. But Captain America is not gonna stand around and let a 'lizard man' tear him to shreds. Cap is not only physically capable to standing up to The Lizard but with his fighting abilities he'll eventually outfight and outwit the Lizard. It would be quite fight indeed. If Cap has his shield than the Lizard will die. He'll cut off limbs till there's nothing left. Without it, Cap will still win. Cap just needs to land his punching bag stunt and literally pulverize the Lizard's head.
Cap is awesome, but against the guy who rampaged all over Spidey? The same Spidey who dodges bullets, electricity and can stop a bus flat out? Yeah Cap is outmatched plain and simple.
Lizard is way too much unless CA fights real dirty like go on survival mode. If I was Cap. The first thing I would try to do and if I can ..is go for the Lizard's eyes anymeans neccesary.
Getting that close to a monster that is much bigger, stronger, faster and has natural weapons is suicide. Especially since the Lizard's HF would repair his eyes quickly.
Cap fressbies his shield decapitate the Lizards head the Cap shoves a grenade in Lizards corpse and blows all his body parts into slab pieces. No regeneration from there.