OXFORD United avoided a potential banana skin in front of the TV cameras to safely secure their passage into the second round of the Emirates FA Cup at non-league Merstham.

The U's may have donated their Ryman Premier Division hosts their half of the gate receipts, but there was no room for such donations on the pitch.

Alex MacDonald's free kick and a Josh Ruffels header put the U's into a 2-0 lead at the break.

The hosts made it far from easy for their higher league opponents at the Moatside, but the 94 places between the sides was most evident in the final third.

A Kane Hemmings brace and Tyler Roberts strike put the tie to bed in the second half as United booked their place in Monday's draw.

The U's made seven changes from the side beaten by Millwall in Sky Bet League One a week ago.

Ryan Ledson was handed his first start after recovering from a knee injury, while Ruffels joined him in the centre of midfield.

Aaron Martin returned to the starting line-up for the first time since last month's Checkatrade Trophy tie at Swindon Town, while Liam Sercombe and Marvin Johnson were made makeshift full backs.

MacDonald, who was named stand-in skipper, Roberts, Ryan Taylor and Hemmings all stepped up from the bench.

Both sides started brightly, with Merstham keen to make the most of their first appearance at this stage of the competition.

It took United ten minutes to get in behind, when Chey Dunkley picked out a scampering Johnson down the left, but his teasing low cross went all the way out for a throw-in.

The visitors needed an early goal to settle any nerves and on 12 minutes they got exactly that.

MacDonald was fouled on the edge of the area and the midfielder picked himself up to curl a wonderful free-kick into the top corner from 20 yards.

The goal quietened the home fans, but Merstham created a chance of their own moments later, only for Martin to block Dan Bennett's effort.

United, though, looked dangerous every time they came forward and Taylor was twice denied by former Oxford keeper Phil Wilson - the second a fine one-handed save.

But just when United thought they had got a foothold in the tie, Merstham began to build pressure and Alex Addai should have done better with a header on the half-hour.

The hosts continued to force their higher league opponents back, forcing the U's to clear their lines on numerous occasions, but they were susceptible to the counter.

And that was how United doubled their lead on the stroke of half-time as Taylor found Johnson, who breezed past Michael Abnett and delivered a delightful ball for Ruffels to powerfully head home.

There was still time for Merstham to create a chance before the break and Reece Hall looked certain to score in the six-yard box, but Dunkley made a goal-saving tackle to deny the striker.

The start of the second half lacked the intensity of the first, but Eastwood made a hash of a clearance and Dan Hector forced the United keeper into low save on 59 minutes.

That opportunity gave the hosts a lift and moments later Tom Kavanagh saw his drilled effort blocked.

But United responded brilliantly and Ruffels played in Hemmings, who coolly slotted home his fourth goal of the season on 62 minutes.

And just seconds later the tie was put to bed as Roberts found space down the right and drilled a low shot under Wilson.

Those goals ultimately killed the game off, but Hemmings should have made it 5-0 on 75 minutes, only to head Taylor's cross horribly wide.

Merstham continued to work hard and look for a goal they arguably deserved, but when they did find the net with eight minutes to go it was disallowed.

Hector swivelled and curled an effort towards the corner which Eastwood palmed into the path of Bennett, who tapped home, but the striker was offside.

They still continued to search for a consolation and Eastwood's outstretched leg denied Omar Folkes.

United's professionalism shone through and they somewhat cruelly grabbed a fifth late on when Hemmings tapped home after Wilson made a great save to deny Johnson.

Merstham: Wilson, Abnett, Campbell, Samuels (Folkes 53), Okoye, Douglas, Bennett, Kavanagh, Addai, Vidal (Henriques 65), Hall (Hector 53).

Subs not used: Bailey-Allen, Hopkinson, Hogan, Smith.

Oxford Utd: Eastwood, Sercombe, Martin, Dunkley, Johnson, MacDonald, Ledson, Ruffels, T Roberts (Rothwell 69), Taylor, Hemmings.

Subs not used: Buchel, Skarz, Lundstram, Nelson, Crowley, Maguire.