Nigel Pearson has lamented his side's ability to defend set-pieces as Bristol City left Kenilworth Road empty-handed.
The Robins dominated possession and arguably had the better chances but were undone by two crosses on either side of half-time.
Despite starting the brighter of the two sides, City fell behind when ex-Rovers defender Tom Lockyer headed home James Bree's corner five minutes before the end of the first half.
