WATCH: Teen Solves Rubik's Cube In Record Time; Fellow 'Speed Cubers' Go Wild : The Two-Way Fourteen-year-old Lucas Etter unmixed a 3x3x3 Rubik's Cube in 4.904 seconds, setting a world record and becoming the first person to break the 5-second mark for solving the puzzle.

WATCH: Teen Solves Rubik's Cube In Record Time; Fellow 'Speed Cubers' Go Wild

Lucas Etter's fingers move so fast, it really looks like the video is in fast-forward. But when the 14-year-old from Lexington, Ky., triumphantly slams the cube on the table, the clock shows the truth: 4.904 seconds, the fastest anyone has ever solved a 3x3x3 Rubik's Cube. Guinness World Records confirmed the feat Tuesday.

The world-record-breaking solve is incredible, but the reaction of Etter's fellow "speed cubers" at Saturday's event in Clarksville, Md., is the sneaky highlight.

Take a look for yourself:

YouTube

Guinness World Records added: "Incredibly, the event had seen the record broken once already earlier in the day, with Keaton Ellis, a fellow speed cuber from Maryland, managing to solve the cube in 5.09 seconds, beating the previous record of 5.25 seconds set by Collin Burns back in April."