O'Meara paired with good friend Tiger Woods to shoot a better ball seven-under 65 and beat the Lake Nona pairing of Sergio Garcia and Retief Goosen by one stroke to earn two points.
Therefore, each player plays two singles matches. A win is worth one point, a tie 1/2 point and a loss zero points. There will be 20 points available on Tuesday. The first squad to 15 1/2 points will win the Tavistock Cup.
In the second match, Robert Damron and Lee Janzen combined to shoot eight- under-par 64. They downed Ben Curtis and Justin Rose by two shots to give Isleworth a 4-0 lead.
Lake Nona, however, claimed the next two matches to square the score at 4-4. In match three, Ian Poulter and Mark McNulty managed a two-under 70, but it was enough to beat John Cook and Charles Howell III by one stroke. McNulty was a late replacement for Nick Faldo.
Maarten Lafeber and Graeme McDowell were paired in the penultimate match and they were two strokes better than the duo of Arjun Atwal and Craig Parry.
In the final match, Stuart Appleby and Robert Allenby also shot 65 to cruise to a two-stoke win over Lake Nona's South African duo of Ernie Els and Trevor Immelman. Els also served as Nona's team captain.
Woods posted three birdies and an eagle, while O'Meara carded two birdies for their seven-under total. Goosen had the low score of his duo after each of the first seven holes, but managed only one birdie in that stretch. He also birdied two of the last six holes, while Garcia posted three birdies for their 66.
Damron birdied two of the first three holes, then birdied eight and nine as he and Janzen made the turn at minus-five. They teamed to birdie three of the last five holes to shoot 64. Curtis and Rose struggled with two birdies and two bogeys over the first five holes.
They ran off four straight birdies from the seventh though to get back in it. Curtis bogeyed the 13th, but came right back with a birdie at the next. Rose closed with a birdie on the last, but it was not enough.
McNulty and Poulter played the front side at even par with a birdie and a bogey. Poulter bogeyed No. 10, but they teamed for three straight birdies from the 12th for the win. Cook and Howell had two birdies and a bogey on the front nine. On the back nine, two bogeys and two birdies left them one behind McNulty and Poulter.
'This is pretty special right here,' said McDowell. 'It is a special event to be a part of. I'm happy my partner carried me around a bit today. It is great to get a point on the board for Nona obviously.'
Lafeber and Parry carried their pairings. Lafeber had the team's low score 13 of the 18 holes and that included four birdies and two bogeys. Atwal also has the team's best score for 13 holes, but was three-over par. Parry, a factor in five holes, had three birdies for their 72.
Allenby had five birdies and a bogey, while Appleby recorded four birdies for their 64. Els like Allenby posted a bogey and five birdies, but Immelman posted a single birdie for their 67.
'The front nine played pretty tough I thought and the back nine gave us more birdies, but they just out-played us down the stretch,' Els admitted. 'We hit some good shots, but couldn't make as many putts as them.'
One special team prize was picked up by Woods today. He posted the longest drive of the day, a 340-yard bomb, to give each of his teammates $10,000.