Their next game sees Pep Guardiola's travel to the winner of Middlesbrough's replay with Newport County, and City are just 11/8 (2.38) to win the competition with bet365. Before the draw was made that price was around 7/4 (2.75) with the same firm.
The tie sees the second and third favourites in the outright market square off at Stamford Bridge, so it's understandable to see the market principles shorten up even further with one of their two main rivals set for an exit before the quarter-final stage.
The online bookmaker have already priced up the match odds between the Premier League pair, making Chelsea 23/20 (2.15) favourites to win in normal time while Ole Gunnar Solskjaer's side are available at 23/10 (3.30) to win in south west London. The draw is a 12/5 (3.40) shot at the time of writing.
Wolves (10/1) needed a late equaliser to force a replay against Shrewsbury Town but the Premier League side are expected to come through that second meeting at Molineux on Tuesday, priced at 2/11 (1.18) to win the game in 90 minutes. Should they emerge victorious, they'll travel to Bristol City.
Having knocked out Liverpool in the third round, Nuno Espirito Santo's side will be a tough task for anyone left in the competition given they're unlikely to rotate their side too heavily in favour of the other competitions - unlike those above them in the betting who have European obligations in the coming weeks.
Unlike Wolves, Palace don't have the relative safety of mid-table to rely upon just yet but a strong line-up against Spurs suggests Roy Hodgson is taking this competition seriously.
The Seagulls will take on Derby County if they manage to get the better of West Bromwich Albion after the pair drew 0-0 at the Amex Stadium.