A Steve Morison penalty and two defensive lapses by struggling Blackpool gifted Millwall a comfortable 3-0 victory at the New Den.Lee Gregory put the Lions ahead with a simple header after a Carlos Edwards long throw was allowed to bounce in the visitors' area after just eight minutes.Neil McDonald's side, the division's lowest scorers, never looked like threatening and were made to rue an early missed header by Uche Ikpeazu.Jed Wallace doubled Millwall's lead in the 24th minute with his first goal for the club when his 20-yard free-kick went straight through the visitors' wall.Two Brad Potts shots from 20 yards and a wild strike from Ikpeazu were Blackpool's best second-half chances while Morison struck the inside of the post with a curling effort.Blackpool's miserable afternoon took another turn for the worse when Hayden White received a second yellow card for a shirt-pull on Shane Ferguson and Mark Cullen had an effort ruled out for offside.The rout was completed by Morison when he converted a penalty awarded for Tom Aldred's handball inside the area.