But new US Open champion Michael Campbell could only manage a 2-over 74 after three successive bogeys from the 16th onward.
Francois Delamontagne matched Goosen's 67, while Ireland's Gary Purphy and Jonathan Lomas of England shot 68s.
No.5 Goosen was unperturbed by his final-round 81 at Pinehurst 11 days ago, which he blamed on an alignment problem with his putting.
Ben Curtis, Jim Furyk and Todd Fischer all shot bogey-free, 7-under 64s, getting within a stroke of the Cog Hill course record and sharing the lead after the first round of the Western Open.
The trio were two strokes ahead of Harrison Frazar, former Western champ Robert Allenby and Chad Campbell.
Fan favorite John Daly, playing his first Western since 1996, finished at 2-under 69 after almost holing his second shot on the par-4 18th.
Tiger Woods and Vijay Singh didn't look like the top two players in the world. Woods, who couldn't get the ball close to the pin all afternoon, shot a 2-over 73 and has some work to do to make the cut. Singh shot 72.
Curtis was a rookie just trying to hold onto his PGA Tour card when he won the British two years ago, beating Singh and Thomas Bjorn by a stroke.
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