'I think it was a good start,' said Els. 'I kept it in play most of the day, I got myself a lot of opportunities and I made some putts. I putted well today.'
Miguel Angel Jimenez, Christopher Hanell and Stephen Dodd share second place at 7-under-par 65. Vijay Singh, who tops the money list on the PGA Tour, was one shot further back at 6-under-par 66 along with Scott Drummond.
Els, who lives on the Wentworth estate and has made the course his own with five Match Play titles, looked quite comfortable on Thursday and hit his tee shot to 12 feet for a birdie at the par-3 second. Els then birdied the par-4 third and chipped in for a birdie at the eighth.
'I know the course so well, and I know the greens very well,' said Els. 'So if I'm going to strike the ball well, I feel I've got a good chance of shooting a good score.'
At the par-4 ninth, Els ran home a 35-footer for his fourth birdie of the front side to go out in 31.
Els kept on rolling on the inward half with a birdie at the par-4 11th and another at the par-5 12th. He then knocked his tee ball to 15 feet for a birdie at the par-3 14th.
With the closing par-5s staring him in the eyes, Els managed only a par at the 17th and missed the green left with his second shot to the 18th. The South African pitched his third to 22 feet and drained the birdie putt to hold the outright lead.
While Els has yet to title at this event, he has come rather close with a trio of runner-up finishes and two more top-10s, including fourth place at last year's championship.
Jimenez, already a three-time winner on the European Tour this season, ran off five birdies over his first nine holes to quickly close in on the top of the leaderboard.
The Spaniard played his second shot to 3 feet for a birdie at the 15th and converted a 6-foot putt for a birdie at the last to finish one shot off the pace.
'I played very well today,' said Jimenez. 'The back nine, I was playing well. I hit as good as the first nine.'
Singh, who captured the 1997 Match Play event at Wentworth, tallied back-to-back birdies starting at the par-4 seventh and added a birdie at the par-5 12th to move to 3 under. The Fijian closed with three birdies over his last four holes for his share of fifth place.
'I played pretty solid. I didn't make too many mistakes,' said Singh. ' I'm very pleased with my round and I'll take that tomorrow and come out firing.'
Defending champion Ignacio Garrido collected four birdies and a bogey on the front side before dropping a shot with a bogey at the 10th. Garrido recovered with a birdie at the very next hole and hit a 5-iron to 24 feet for an eagle at the par-5 12th.
'I'm very happy,' said Garrido, who has missed five of eight cuts this season. 'So very happy to be in contention.'
The Spaniard then mixed a birdie and a bogey down the stretch for a round of 67. He was joined by 2002 Volvo PGA champion Anders Hansen, Justin Rose, Angel Cabrera, Andrew Coltart, Nicolas Colsaerts, Richard Green and David Gilford in a tie for seventh.