He narrowly won the Philadelphia portion of the district, but DeLissio dominated in Montgomery County and will face Republican William Pounds in the fall.
Other incumbents were less fortunate. State Sen. LeAnna Washington and state Rep. J.P. Miranda, both of whom are facing felony corruption charges, lost their primaries, as did freshman state Rep. James Clay.
Victors in those races said that, given the delegation's recent string of scandals, it was a good time for Philadelphia to have some fresh blood in the Capitol.
"Anyone that comes in and wins an election - and the people give them that vote of confidence - has to have some level of integrity and character," said Leslie Acosta, who won the four-way primary that sank Miranda.
Acosta, whose father was a state representative, said that four members of the delegation who allegedly took cash from a lobbyist working with the state Attorney General's Office should step down.
"If people do that gracefully and accept and acknowledge their wrongdoing, that would be the best course," said Acosta, who does not have a GOP opponent for the North Philadelphia district.
State Rep. Vanessa Lowery Brown, the only member accused of accepting cash who had primary challengers, won easily.
Acosta teamed up in the campaign with state Sen. Tina Tartaglione, who repelled two challengers in a nasty primary.
Clay, the freshman lawmaker, failed to make inroads with the party in his two-year term and lost by 80 votes to Jason Dawkins, one of five candidates backed yesterday by City Councilwoman Maria Quinones-Sanchez.
"This time the voters have made their choice and pretty much made it very clear," said Dawkins, who worked in Sanchez's Council office. "The voters want to see something new in the Philadelphia delegation."
Dawkins, who has no opponent in November, was the only victory for Sanchez. Her husband, Tomas Sanchez, lost to Tartaglione.
Mike Driscoll, who worked in Gov. Bob Casey's administration, won the Democratic primary for the Northeast Philly seat being vacated by state Rep. Mike McGeehan. He will face Michael Tomlinson in the general election. He enjoyed strong support from party officials and unions like the International Brotherhood of Electrical Workers Local 98.
Lawyer Art Haywood III defeated Washington in the three-way Democratic primary for a Senate district that covers parts of Northwest Philly and Montgomery County. He's up against Republican Robin Gilchrist.
U.S. Rep. Bob Brady, chairman of the Democratic City Committee, said that although he doesn't like losing incumbents, there's only so much the party can do.
"It's tough to win when you're indicted," Brady said. "Primaries are a family squabble. We're all back together again."
Some observers said that, despite the newcomers' optimism, it will take more than a few new faces to change the city's image in Harrisburg.
"I don't think anything really changes in terms of the clout of the delegation because in both the House and the Senate, Democrats are in the minority," political consultant Larry Ceisler said of Philly's almost entirely Democratic group of lawmakers.
Farther down on the ballot, developer Ori Feibush's bid to take out 36th Ward Leader Anna Verna, the retired Council president, appears to have fallen short.
Committeepeople won't vote for ward leaders for three weeks, but sources said Feibush, who is expected to challenge Councilman Kenyatta Johnson next year, did not come close to landing enough support for the coup.
Feibush did not respond to requests for comment.
On Twitter: @SeanWalshDN