With 93 percent of precincts reporting, Sanders had 53 percent of the vote to 47 percent for Hillary Clinton.
Clinton led state polls by about 7 percentage points before the Tuesday primary. Given that Democrats award their delegates on a proportional basis, Sanders was likely to net just a handful in Indiana. Clinton, meanwhile, has been previewing her general election message, spending this week on a tour of Appalachia.
On the cash front, the campaigns released their April fundraising numbers, with Clinton beating Sanders $26.4 million to $25.8 million. Bernie Sanders (D-Vermont) was announced the projected victor of the Democratic primary in Indiana.
Sanders now needs to convert his IN momentum into a string of victories through the June 7 California primary to have any hope of securing the Democratic nomination. Earlier Tuesday, Clinton told MSNBC's Andrea Mitchell that she was "really focused on moving into the general election".
The Sanders campaign is eager to remind voters of that fact, and is pushing to pull off the same feat in 2016.
And this swell of cross-party support is great news for the fall, but for now, it's making it hard for Democrats to come to a consensus on a candidate without the fear of creating a climate that keeps voters at home in November. The Vermont senator acknowledged that he faced an "uphill climb" to the Democratic nomination but said he was "in this campaign to win and we are going to fight until the last vote is cast".
But Clinton now leads Sanders on several measures raw vote, pledged delegates and the overall delegate count including superdelegates and is on a almost unstoppable track to capture the Democratic nomination by next month.
Sanders acknowledged previously that it would be a big challenge to amass enough delegates to catch up with front-runner Clinton. Only 30 percent would like to see him bow out now.
Exit polls conducted by Edison Research for The Associated Press showed Clinton was drawing the support of black voters and Sanders was attracting younger voters.