The 34-year-old Brazilian had 24 points in the modified Stableford scoring system that gives players eight points for double eagle, five for eagle, two for birdie, zero for par, minus-one for bogey and minus-three for double bogey or worse.
Winless on the PGA Tour, Rocha opened birdie-birdie-birdie-eagle on Nos. 10-14 and overcame three bogeys.
J.J. Henry had his second eagle of the tournament, and John Mallinger had six birdies to move into a tie for second at 22.
First-round leader Andres Romero, of Argentina, and Arjun Atwal, of India, had 21 points, and 2010 Reno-Tahoe winner Matt Bettencourt followed with 20. John Daly is seventh with 19. He birdied six of his last 10 holes.
WEB.COM TOUR: In Omaha, Neb., first-round co-leader Luke Guthrie shot 8-under-par 63 to take a three-stroke lead after two rounds of the Cox Classic at Champions Run.
Guthrie is at 17-under 125 through 36 holes.
Tag Ridings and Brian Stuard also shot 63s in the second round. Ridings is second at 128, while Stuard is third at 129.
Rob Oppenheim shot 61, the low round of the day, to vault from 74th into a tie for fourth at 130 with Peter Lonard, Brad Fritsch and Steve LeBrun.
Augusta’s Scott Parel shot 68 for the second consecutive day and made the cut on the number. Aiken native Matt Hendrix rebounded from an opening 73 to shoot 65 but missed the cut by two shots.
CHAMPIONS TOUR: In Blaine, Minn., 65-year-old Gil Morgan shot his age for a share of the lead after the first round of the 3M Championship.
“I didn’t have too many mistakes, I didn’t miss many greens, but I had a few opportunities that kind of slipped away putting-wise,” Morgan said.
Chien Soon Lu, Steve Pate and Peter Senior also shot 7-under-par 65s at the TPC Twin Cities.
Joel Edwards, Tom Jenkins and Mark McNulty are a stroke back. Past event champions David Frost, Bernhard Langer and D.A. Weibring are at 67 along with Joe Daley, Jeff Hart and Willie Wood.
On an ideal sunny day with a slight breeze early, 49 of 81 players shot below par.
Morgan had seven birdies in his bogey-free round. He won the last of his 25 Champions Tour titles in 2007 at Pebble Beach.
Tom Lehman, a former University of Minnesota player who teamed with Arnold Palmer to design the TPC Twin Cities, had 68. Lehman grew up in Alexandria, Minn.
Defending champion Jay Haas opened with 71.
Augusta native Larry Mize had 73.