[1] Titenis is considered one of Lithuania's top male swimmers, having achieved more than a hundred titles at the national championships, and having broken numerous records in men's breaststroke (50, 100, and 200 m), and medley relays (200 and 400 m).

Titenis made his international debut at the 2006 FINA Youth World Swimming Championships in Rio de Janeiro, Brazil, where he earned a bronze medal in the men's 200 m breaststroke, with a time of 2:16.57.

[4] Titenis guaranteed his spot on the Lithuanian team for the 2008 Summer Olympics in Beijing, by obtaining an A-standard entry time of 1:00.92 (100 m breaststroke) from the 2007 FINA World Championships in Melbourne, Australia.

[5] On the first night of the Games, Titenis challenged seven other swimmers in a top seeded heat, including former Olympic medalists Roman Sludnov of Russia (2000), and Brendan Hansen of the United States (2004).

[7] The following morning, Titenis fell short in his bid for the final, as he placed twelfth in the semifinal run by five hundredths of a second (0.05) behind Bulgaria's Mihail Alexandrov, with a fourth slowest time of 1:00.66.

[13] For his third and final individual event, 200 m breaststroke, Titenis rebounded from his upset in two previous races, and shared a bronze medal triumph with Australian swimmer and world-record holder Christian Sprenger, clocking at 2:07.80.

[28][29][30] Achieving his best finish, Titenis became the second Lithuanian swimmer in history to reach an Olympic final since Vytautas Janušaitis did so in 2004, until his teammate Rūta Meilutytė surprisingly won the gold medal in the same stroke by the following evening.