According to the unofficial overnight figures the average share of 40.2% for the match was ITV's best peak-time performance since the Fifa World Cup last June.
BBC One lost out to the fixture, with 'EastEnders' at 7.30pm pulling in 6.6m viewers and a 34% share and 'Holby City' at 8pm-9pm getting 5.3m viewers and a 23% share.
The 8.9m audience for the match exceeded the 7.4m who watched ITV1's coverage last week of the first leg of the other semi-final between Manchester United and Italian club AC Milan.
Liverpool went through to the final by beating Chelsea 4-1 on penalties after the tie was drawn 1-1 on aggregrate.
If Manchester United progress tonight, it will set up an all-English final in Athens and a banker for ITV1 on Wednesday May 23.
Channel 4 scheduled the return of its series aimed at women with body issues, 'How to Look Good Naked' against the football at 8pm-9pm. The first of eight programmes providing advice on achieving a better body with plastic surgery brought in 2.5m viewers and an 11% share.