Thursday's action was completely washed out, forcing the first round to Friday. The second round will be contested on Saturday. The current plan, weather permitting, is to play the final 36 holes on Sunday.
The International uses the modified Stableford scoring system in which players are awarded eight points for double-eagles, five for eagles and two for birdies. They lose one point for bogeys and three points for double-bogeys or worse.
Brandt Jobe posted 13 points in the opening round to take second place. Charles Howell III and D.A. Points are one point back at 12. Geoff Ogilvy and Tim Petrovic share fifth place with 11 points.
Mayfair picked up two points with a 15-foot birdie putt on the first at Castle Pines Golf Club. The five-time winner on the PGA Tour drained a 12-foot birdie putt on the third for two more points.
He collected another two points with a 10-foot birdie putt on four. Mayfair moved to eight points as he sank a four-foot birdie putt on the sixth.
Mayfair, who turns 39-years-old on Saturday, parred his next 10 holes. The Arizona native ran in a 70-foot eagle try on 17 for five points to jump to 13.
'Get a good two-putt birdie, we'll go on,' said Mayfair of what he thought about his putt on 17. 'One of those long ones. My caddy told me it went right in the heart. I didn't think it was going to get there at first, but it did.'
He made a 12-foot birdie try on the last for his final two points.
'I got off to a good start,' Mayfair said. 'Birdied four of the first six holes out there. Obviously, I wasn't quite sure what the golf course was going to be like today after all the rain of Thursday. I thought the golf course was in great shape.'
Jobe, who owns nine international victories, got up and down for birdie at the first to gain two points. His 12-foot birdie putt on three moved him to four points.
The UCLA alum pitched his third to five feet to setup birdie on the par-five eighth. His three-foot birdie putt at the ninth gave him eight points on his front nine.
Jobe, who turned 40-years-old this past Monday, flew the green at the 11th and took an unplayable lie penalty. He walked away with a double-bogey to drop to five points.
The Oklahoma-native sank a 12-foot birdie try on the 12th to get two of those points back. Jobe missed a short par putt on 13 to lose another point.
Jobe birdied the 14th to climb back to eight points. He dropped his second shot to the par-five 17th within two feet of the cup. He kicked in that eagle try to leap into second place with 13 points.
'I played real well on the front nine,' Jobe said. 'The birdies I made weren't long putts or anything like that, so that was kind of nice. Of course when you make eagle at the 17th, it's a nice way to end the day.'
Corey Pavin and Jonathan Byrd gathered 10 points on Friday. They share seventh place with Daniel Chopra, Chris Anderson and Cameron Beckman. Joe Ogilvie, Stewart Cink and Ben Crane are one point back with nine.
Defending champion Rod Pampling shares 40th place with five points.