Furyk and Howell each carded rounds of 65 to jump to the top of the leaderboard. Furyk's six-under round came at the TPC Canyons course, while Howell's seven-under round came on the TPC Southern Highlands course.
During the first three rounds of the tournament, players are paired with amateurs and will rotate between the TPC Summerlin and TPC Southern Highlands, each par-72 courses, and the par-71 TPC Canyons course. The final two rounds, following the 54-hole cut, will be played on the TPC Summerlin course.
Furyk began his second round in similar fashion to his first. He parred the first three holes, then notched his first birdie at the par-5 fourth. He followed that with a birdie on the fifth. He later posted his final birdie on the front side at the eighth.
'I shot a good, solid score and put myself in position,' said Furyk, who was in the fourth group to tee off. 'I kept it in play and hit it straight. I gave myself a lot of opportunities for birdie from 15-feet and in.'
Furyk, who is one of four players without a bogey through two rounds, continued his hot play early on the back side. He posted consecutive birdies starting at the 11th, when he knocked his approach within one foot of the cup. He posted his final birdie of the day at the par-4 14th from six-feet out.
'You have to stay patient and keep focused,' Furyk said. 'You can't give up birdie chances. The third round is still to be played, good thing for me is they are all at Summerlin.'
Howell meanwhile posted bookend birdies at the first and ninth. In between, he posted consecutive birdies starting at the fifth, when he drove the green on the 365-yard par-4. He two-putted from there, then stuck a sand-wedge within four feet at the next.
'Now that I've won a tournament, I'm probably a little more relaxed,' said Howell, who earned his first PGA win at the Michelob Championship last week. 'That's probably the No. 1 thing. I'm just more relaxed.'
Howell jumped to 12-under with a birdie at par-3 12th followed by an eagle at the par-5 13th. He hit a two-iron to the 577-yard hole within 25 feet of the cup.
'I know in a perfect world you're not supposed to think about those things,' Howell said in reference to qualifying for the Tour Championship and next spring's Masters. 'But they're in the back of your mind.'
Howell is looking to become the first player to capture tournaments in consecutive weeks since Tiger Woods accomplished the feat in March 2001, when he won the Bay Hill Invitational and The Players Championship. David Duval is the last player to win his first tour event one week and claim his second victory the following week. In 1997, Duval won the Michelob Championship then claimed the Walt Disney World/Oldsmobile Classic.
Rory Sabbatini, Scott Verplank, Phil Tataurangi, Duval, J.L. Lewis, Jonathan Byrd, Robert Gamez and Steve Allan are two shots off the pace at 10-under-par.
Joe Durant, Stuart Appleby, Billy Mayfair, Ben Crane, Bart Bryant, Jay Don Blake, Brent Geiberger, Steve Lowery, Billy Andrade, Olin Browne, Tim Petrovic, Paul Stankowski, Scott McCarron and PGA Champion Rich Beem are one shot behind that group at minus-nine.
A pair of two-time PGA Tour winners, Stewart Cink and Robert Allenby, lead a large group at eight-under. Allenby carded a three-under-par 69 to extend his Tour-best streak of consecutive rounds at par or better to 19.
Overnight co-leader Lee Janzen, the 1998 U.S. Open champion, fell into a tie for 46th place with a second round 74. He now stands at seven-under.
Defending champion Bob Estes is in danger of missing the cut as he stands at two-over-par after a second round 75 at the TPC Summerlin course.
Full-field scores from the Invensys Las Vegas Classic