Eduardo Romero, Michael Campbell, Andrew Coltart, Trevor Immelman and Kenneth Ferrie share second place at 5-under-par 67.
Howell, who has posted a pair of top-10 finishes on the European Tour this season, started on the 10th hole of the Arden course and collected back-to-back birdies starting at the par-5 12th.
The 28-year-old added a birdie at the par-5 17th to make the turn at 3 under and continued to take advantage of the par-5s with a birdie at the third.
Howell then birdied the sixth before going after the par-5 seventh.
His approach failed to find the putting surface and nestled into the thick rough to the right of the green. Howell was left with a decent lie, however, and played his third shot to 6 feet.
The Englishman drained the birdie putt and parred his two remaining holes to complete a bogey-free round.
'Pretty tough conditions today,' said Howell, who won the Dubai Desert Classic in 1999. 'I drove the ball really well and I didn't make any stupid mistakes. I played the par-5s as you should.'
Immelman, who won his second straight South African Open earlier this year, also played the back side first and picked up three birdies over his first nine holes.
The South African birdied the first but found trouble with a bogey at the very next hole.
Immelman came back with a birdie at the fourth and dropped his tee shot inside 5 feet for a birdie at the par-3 fifth.
'I just rolled a few putts in and it was exciting for me because that's what I've been struggling with over the last couple of months,' said Immelman. 'It was great for me to be able to see the ball go in.'
Romero, who will celebrate his 50th birthday this July, got to 6 under on his round with an 8-foot birdie putt at the seventh but stumbled to a bogey at the ninth, his last, for his share of second.
Brian Davis, Jarrod Moseley, Raphael Jacquelin, Maarten Lafeber and Stuart Little are tied for seventh place at 4-under-par 68.
Darren Clarke finished four shots off the pace in a group at 2-under-par 70 that featured Sandy Lyle, Ian Woosnam and Paul McGinley.
Defending champion Greg Owen mixed three birdies and three bogeys to finish at even-par 72 in a group that includes Retief Goosen and Colin Montgomerie.