After demolishing Middlesbrough 6-1 in the second leg of their EFL Cup semi-final on Tuesday night, the Blues should have been confident of scoring at least once at Stamford Bridge against the Villans, although Unai Emery's men were able to hold out for a draw
Mauricio Pochettino would have been the happier of the two managers at the half-time whistle but Villa were closest to taking the lead in the first period, with a fortuitous deflection off Douglas Luiz making the net ripple, however the goal was ruled out as it hit the Brazilian's arm.
The hosts seemed to lack a focal point in the opening 45 minutes and Pochettino made some changes to alter their attacking chemistry, with the likes of Armando Broja and Mykhaylo Mudryk making their way onto the field, however the West Londoners were unable to breach the net of Emiliano Martinez.
Chelsea's hopes of completing a cup double are still alive, however a midweek trip to Villa Park in the upcoming replays means that the eight-time winners will need to work hard for their spot in the fifth round.
Another Premier League team who will be battling away in a replay next month is Nottingham Forest, with Nuno Espirito Santo's charges unable to find the net against Championship outfit Bristol City.
The second-tier Robins have already claimed the scalp of West Ham United in the previous round of this competition and were looking for a second memorable night at Ashton Gate in the space of 10 days.
Liam Manning's men did not manage to register a shot on Matt Turner's goal, though, with the Tricky Trees coming closest to booking their spot in the fifth-round draw.
The best chance of the West Country contest fell to Forest striker Wood, who saw his close-range header saved by City goalkeeper Max O'Leary after an hour.
Before a second meeting between the sides at the City Ground next month, Bristol City travel to Coventry and host Leeds United in the Championship.
Speaking of the Sky Blues, following a 2-1 win at Hillsborough in the league last weekend, Mark Robins's side were denied a spot in the last 16 at the same venue by a late Sheffield Wednesday equaliser.
Making his first start since arriving earlier in the month from Norwegian side Sarpsborg 08, midfielder Victor Torp rifled in a long-range strike past Pierce Charles to give the visitors a one-goal advantage at the break.
The Dane was employed alongside Ben Sheaf in the Coventry engine room, and the 24-year-old's peach of a goal was reminiscent of similar strikes from Gustavo Hamer last season.
Staring back-to-back defeats against the Sky Blues in the face, Wednesday upped the ante in the second period and managed to level the contest in the final 10 minutes.
Barry Bannan played the ball out to winger Djeidi Gassama on the edge of the box, before the Frenchman created a yard of space and slid the ball into the net, beating Ben Wilson at his near post.