Eastleigh manager Martin Allen was wreathed in smiles during what he described as one of the highlights of his career. And then the game started.

Mad Dog admitted to being close to tears as he walked across the turf to the away dug to a standing ovation from the Brentford fans, in his first game back at Griffin Park since leaving more than a decade ago.

Suffice to say there was not such a warm welcome from Brentford on the pitch.

They showed the huge gulf that exists between the Championship and the National League in netting their five first-half goals in front of the 1,428 Eastleigh fans.

As their manager Dean Smith said: “This is not being disrespectful to Eastleigh, we’re both teams of professional footballers but I would expect us to be quicker, fitter, stronger because the Championship demands that.

“Further down the leagues it’s not as intense.”

Goodness knows what the scoreline would have been if Brentford had selected Scott Hogan, their 14-goal top scorer.

Even without star striker, who has been linked with Newcastle and West Ham in recent weeks, Brentford became the first side to score five goals in the first half of an FA Cup tie for six seasons (Carlisle United were the last side to achieve the feat in a first round tie against Tipton in November 2010).

Eastleigh fielded a makeshift line-up, including only four survivors from the team that beat FC Halifax Town in the last round and, in the absence of the suspended Joe Partington, just one (James Constable) from the team that lost at the same stage of last season’s FA Cup at Bolton Wanderers.

With Reda Johnson hamstrung, Allen fielded deployed central defenders with only 23 starts for the club between them as well as an 18 year-old on his FA Cup debut in 18 year-old Wolves starlet Hakeem Odoffin.

Connor Essam, another loanee, has 15 of them. And the back three was playing in front of a goalkeeper making his debut in veteran former Arsenal custodian Graham Stack, whose experience was preferred to the form of rookie Mark Childs.

Allen described his “mix-and-match” squad as being “like a box of Quality Street”, but all the quality came from Brentford.

Eastleigh were soon exposed by a through ball inside Hoyte, who suffered a hamstring injury as he tried to keep up with Lasse Vibe.

Vibe gained the advantage by knocking Hoyte off balance, but referee Peter Bankes did not blow his whistle until Stack brought down the Danish international.

French defender Yoann Barbet sent Stack the wrong way in scoring his first goal for the club, into the bottom left corner.

Transfer-listed Ayo Obileye, on his full Eastleigh debut, dropped back to replace Hoyte when the former Arsenal trainee limped off. Jai Reason, one of only four available Spitfires substitutes, came on.

But Eastleigh’s day soon got worse as rookie left-back Tom Field scored the first of his two goals on what was an outstanding debut.

Former Saints academy defender Harlee Dean began a slick move orchestrated by Romaine Sawyers.

Eastleigh backed off and Sawyers produced a delightful outside- of-the-boot chip which Field converted with a diving header at the far post.

Obileye was soon denied from close range by Daniel Bentley from Luke Coulson’s inswinging free kick, but when Ryan Bird’s shot was blocked, it took only four passes for Brentford to set up Vibe, who curled in a wonderful third goal with the outside of his right foot.

Eastleigh pulled one back when Bentley, with Bird and Obileye in close proximity, mistimed his punch from Coulson’s inswinging corner.

The ball came off the back of Bentley’s hand on to the bar before falling at Obileye’s feet inside the six-yard box.

The Spitfires were threatening from set pieces and Michael Green hit the far post from the other flag as Bentley desperately tried to get a touch.

But Brentford soon restored their lead. Josh McEachran, a £750,000 buy from Chelsea 18 months ago, showed his pedigree with a through ball that bypassed three Eastleigh defenders.

Field did the rest, stroking in his second from inside the area.

With their three-goal lead restored, Brentford completed the rout in the seconf minute of first-half injury time.

Following McEachran’s left-footed chip over the top, Vibe teed up Sawyers with a delightful first touch and the midfielder fired a spectacular right-footed strike into the bottom corner from outside the area.

It was a sobering end to an awful first half.

With the damage done, Eastleigh at least restored some pride in the second half. Mikael Mandron had a shot cleared off the line, Scott Wilson provided much-needed pace on the break and Jai Reason’s Le Tissier-like chip was tipped over.

Obileye should have netted a second consolation but put a free header over the bar, while Stack helped ensure no further goals were conceded as Brentford coasted to the final whistle in the knowledge tougher opposition awaits in the form of Newcastle United next week.

Encouraged by his side’s second-half display, Allen was smiling again as he posed for pictures and signed photographs on his way out of Griffin Park.

At least now he can return to the task of leading Eastleigh to the sort of success that would make him a fans’ favourite at the Silverlake Stadium - starting at home to Forest Green Rovers tomorrow night.