Millwall's unbeaten run in the Championship stretched to seven games in a feisty stalemate with Middlesbrough at the Den.
Five yellow cards were handed out in a stop-start first half as both sides struggled to carve out clear-cut chances.
Millwall failed to register a single shot against Blackburn on Tuesday and this was another match where defences came out on top.
Marcus Tavernier rattled the crossbar with a thunderbolt free-kick from 35 yards out for Middlesbrough in the opening minutes.
Millwall goalkeeper Bartosz Bialkowski came out to deny Folarin Balogun before Paddy McNair's effort was dug out from under the crossbar for the visitors.