Leeds United are safely through to the Johnstone's Paint Trophy Northern Section semi-finals.

Accrington Stanley, Bradford and Carlisle will be joining them in the last four, with all four sides now a step closer to Wembley.

Leeds boss Simon Grayson has taken the competition seriously this season and named another strong side in the Whites' meeting with Grimsby.

That proved to be a wise decision as the League One leaders ran out comfortable 3-1 winners at Elland Road.

An Oliver Lancashire own goal after 40 minutes set them on their way, while Neil Kilkenny added a second on the stroke of half-time.

The free-scoring Jermaine Beckford wrapped things up 10 minutes after the interval, ensuring that a spectacular 57th minute volley from Peter Sweeney counted as little more than a consolation for the Mariners.

Accrington's progress was slightly less convincing, with Stanley pushed all the way by Bury at The Fraser Eagle Stadium.

The hosts edged into a 2-0 lead courtesy of a first-half brace from Michael Symes (2 & 40), but took their foot off the gas thereafter.

That allowed Danny Racchi to pull one back for the Shakers on 41 minutes and Mike Jones restored parity three minutes after the break.

That is how it stayed until eight minutes from time when Robert Grant snatched a dramatic winner for Accrington.

Carlisle recovered from going a goal down against Chesterfield to prolong their cup challenge.

Darren Currie stepped off the bench for the Spireites to convert from the penalty spot moments before the half-time whistle.

The Cumbrians refused to buckle, though, and hit back through Matty Robson (62), Peter Murphy (69) and Adam Clayton (78).

Bradford and Port Vale required penalties in order to find a winner at Valley Parade, with the Bantams eventually coming out on top.

A topsy-turvy encounter saw Vale break the deadlock through John McCombe after 27 minutes.

Michael Flynn (49) and James Hanson (70) then turned the tie on its head before Robert Taylor ensured the game would go to spot kicks when he struck with 15 minutes remaining.

An epic shootout was finally settled by Steve Williams, following more heroics from Simon Eastwood, with Bradford prevailing 5-4.

In the southern section, MK Dons comfortably booked a place in the Sothern Section semi-finals, while Herford upset Leyton Orient on penalties.

Elsewhere, Norwich eliminated Swindon after a tense shoot-out at the County Ground.

Paul Ince's Dons have their eyes on promotion from League One, but they would also relish a repeat of their 2008 success in the Football League trophy.

They made light work of Northampton at Stadium:MK as they recorded a 3-1 win, with all of the home side's goals coming in the first half.

Hereford shocked League One Leyton Orient with a 3-2 victory on penalties at the Matchroom Stadium.

Orient had only taken the game to spot kicks as Jason Demetriou's last-gasp equaliser snatched a 1-1 draw in normal time.

Swindon went out on home soil after losing 5-3 on penalties to Norwich following a 0-0 stalemate.

Southampton play Charlton at St Mary's on Wednesday in the fourth semi-final of the Southern Section.