Owen and Palmer appeared in an EastEnders spin-off together in 2002
Ricky Butcher and Bianca Jackson's return to EastEnders attracted 9.7 million fans, according to overnight viewing figures.
It was the first time in six years that viewers saw actors Sid Owen and Patsy Palmer appear in the same episode of the BBC One soap.
The previous Tuesday's episode, attracted 7.5 million viewers.
Janine Butcher, played by Charlie Brooks, also appeared in the episode showing her father Frank's funeral.
The Welsh actress left the show in 2004 after her character was wrongly arrested for the murder of Laura Beale (Hannah Waterman).
Tuesday's episode, which peaked half-way through with an audience of 10.1 million viewers, also saw the return of Diane Butcher, played by Sophie Lawrence.
Ricky and Bianca endured a stormy relationship which eventually ended. The pair made a brief comeback in an EastEnders spin-off in 2002.
Ricky arrived back into Albert Square with a new fiancee, while Bianca returned as a single mother, struggling to survive.