Sadauskas qualified for the men's 100 m freestyle at the 2012 Summer Olympics in London, by breaking a meet record and eclipsing a FINA B-standard entry time of 49.54 seconds from the Open Luxembourg Nationals in Luxembourg City.. At the 2012 Summer Olympics, he challenged seven other Olympians in the fifth heat, including three-time Olympian and UC Berkeley graduate Dominik Meichtry of Switzerland. Sadauskas edged out Meichtry to take a fourth spot by 0.17 of a second, outside his entry time of 49.78 seconds. Sadauskas failed to advance into the semifinals, as he placed twenty-eighth overall in the preliminaries.