A Super Mario Bros. speedrunner seemingly did the impossible by beating his own "impossible" world record in the classic NES game. 

Twitch streamer Niftski completed Super Mario Bros. in 4:54 and 798ms on Sunday. This edges out his previous record 4:54 and 881ms set last December by 3ms, or five frames. 

Niftski was the first Super Mario Bros. speedrunner to complete the game in less than 4:55, a feat considered to be almost impossible for players. To give some perspective, the first run under five minutes was done back in 2010. It took 11 years to beat that time by another 5 seconds. 

An absolute perfect run has a time of 4:54 and 265ms, which was done in a tool-assisted run, meaning all the controller inputs were programmed and designed to be so optimized that humans wouldn't be able to replicate it. 

Niftski said this run will likely be the last to not include a new tactic on the second level of world 4 that he calls "Lightning 4-2." It's a trick that can shave even more milliseconds from his time, but it requires incredibly accurate inputs to pull off.