LOS ANGELES — Eric Garcetti is a Rhodes scholar and such a talented piano player that he seemed as capable of becoming a professional musician as a politician like his father. One-time cheerleader Wendy Greuel found herself lifting spirits in her early career, but not beneath a scoreboard. She was a City Hall aide helping the homeless in some of the city’s destitute corners.
The rival Democrats are now headed for a May 21 runoff in the race to become mayor of Los Angeles.
Some of the differences between them are obvious. Greuel, 51, is trying to become the first woman to win the office, while Garcetti, 42, could become the first Jew elected to the job.
But they are alike in many ways that might make it hard for voters to distinguish between them, with liberal pedigrees and long experience at City Hall.
A key challenge for both will be standing out and connecting with voters who supported someone else in the primary or didn’t go to the polls.
‘‘In order to win the election, you have to change people’s minds,’’ said Raphael Sonenshein, executive director of the Pat Brown Institute of Public Affairs at California State University, Los Angeles.
Both candidates went on the attack on Wednesday.
Greuel depicted her rival as a creature of a City Hall bureaucracy, resistant to change. Garcetti suggested Greuel would answer to unions and others who helped bankroll her campaign.
Garcetti, a city councilman, and Greuel, the city controller, easily outdistanced their rivals Tuesday after a lackluster campaign that was snubbed by many voters.
Garcetti topped the field, carrying 33 percent of the vote. Since no candidate collected the majority needed to win outright, he will face Greuel in the runoff. She had 29 percent of the vote, accordingly to preliminary returns.