They played against each other exactly two times. In 2008 when Lillard was a true freshman and Jimmer was a sophomore, Jimmer had 18 and Lillard has 2 points on 4 shots. So he definitely outscored Lillard in that one, but Lillard was a true freshman playing in his 7th college game and wasn't a key part of Weber's offense.
In 2009 when Lillard was a sophomore and Jimmer was a junior, they each scored 23 points, but Lillard was 8-16 from the field and Jimmer was 5-13. Advantage probably goes to Lillard for that one.
Lillard was injured the following year when Jimmer was a senior.