Chris Porter and Brad Walker secure Crewe's victory over Grimsby

Chris Porter and Brad Walker marked their recalls with goals as Crewe boosted their Sky Bet League Two survival hopes with a 2-0 victory over Grimsby.First-half strikes from Porter and Walker ensured the Railwaymen put a nine-point cushion between themselves and the bottom two with their second win in three games. A lively opening saw Diallang Jaiyesimi thwarted by a reflex save from Ben Garratt after the on-loan Norwich winger latched onto a high delivery across the box from Ben Davies.Crewe were ahead in the 12th minute as Porter netted his 11th goal of the campaign, converting Zoumana Bakayogo's cross following a powerful run. Ben Killip turned away a fierce angled drive from George Cooper, who looked to have teed up Porter for his second with a pinpoint ball, only for the veteran striker to miscue his effort.But there was no doubting defender Walker's connection when he doubled Crewe's lead in the 34th minute. Killip failed to get any distance palming away Cooper's free-kick, only for it to be volleyed back over his head into the far corner.Grimsby improved after the break, but could have been further behind when Cooper struck the woodwork with a left-footed curler. Luke Summerfield's thunderbolt which flew inches wide was the closest they got to reducing the arrears.