Tiger Woods, world number one and four-time champion, finished the first round on even-par after he parred the first 12 holes before going bogey, bogey, eagle on his way to a 72.
Rose, who tied for fifth at last year's Masters, was pleased to rebound from his stuttering start.
"I didn't feel that comfortable out there on the course but I made a great swing into six, hit it to five or six feet," the 27-year-old told reporters.
"You can't win the tournament the first day, you can only lose it. I haven't lost it, so it's a great day."
Justin Rose |
"I hadn't putted well the first few holes, but making that slippery little putt settled me down.
"Being in the lead on day one, it really means nothing," Rose added.
"You can't win the tournament the first day, you can only lose it. I haven't lost it, so it's a great day."
Immelman, 28, admitted his round was a somewhat unlikely performance considering his results so far in 2008.
The 2006 USPGA Rookie of the Year had been sidelined part of last season with a stomach parasite.
Staying patient
"I've been struggling through a few things and each week I've kind of felt like I chipped away at something new and started getting better," Immelman said.
"The results have been pretty frustrating and pretty disappointing... I knew I just had to stay patient with myself because I know it's in there somewhere."
Woods, who has set his sights on becoming the first professional to achieve a calendar slam of the four majors, struggled to stay level after 12 holes before bogeying 13 and
14.
"I didn't really get anything going my way today."
Tiger Woods |
However, he chipped in from behind the green to eagle the par-five 15th before parring the last three holes to finish four strokes off the pace.
"I didn't really get anything going my way today," the 32-year-old American said.
"I played a lot better than what my score indicates. I hit a lot of good putts, nothing really went. I just had to stay patient out there.
"The way the golf course plays now, you don't really shoot low rounds here any more. You've just got to plod along. It's playing more like a US Open than it is a Masters."
Britain's Lee Westwood, four under with two holes to play, bogeyed the 17th in fading light on his way to a 69 and a tie for third with Americans Brandt Snedeker and Masters debutant Brian Bateman.
Meanwhile, Britain's Ian Poulter hit a spectacular hole-in-one on the par-three 16th, acing with an eight-iron from 169 yards, to help him to an opening round 70 in his fourth Masters appearance.