Updated: Saturday, 31 May 2014 05:11 | By Agence France-Presse

McIroy endures tough day at Memorial

Former world number one Rory McIlroy came back to earth with a thud on Friday with a six-over par 78 in the second round of the Memorial.

McIroy endures tough day at Memorial

Rory McIlroy of Northern Ireland watches his tee shot on the 17th hole during the second round of the Memorial Tournament at Muirfield Village Golf Club on May 30, 2014 in Dublin, Ohio - by Andy Lyons

McIlroy, who arrived at this Jack Nicklaus-hosted US PGA Tour event off a win in the European PGA Championship at Wentworth, had seized the lead with a first-round 63 on Thursday.

But after a bogey at his opening hole, the 10th, and a birdie at 12 he had double bogeys at the 13th, 14th and 15th to lie six-over for the day after his first six holes.

McIlroy three-putted the 13th from 75 feet and was in the water at 14. He almost reached the par-five 15th in two, but double-hit a chip.

A bogey at 18 saw him make the turn in seven-over 43 -- and even a second nine that included two birdies and one bogey did little to help his cause.

His 78 left him on three-under 141, nine shots off the lead of England's Paul Casey, who fired a six-under par 66 for the clubhouse lead on 12-under 132.

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