Johnson and Palmer defeated the Czech Republic's Jiri Novak and David Rikl 6-4, 4-6, 6-3, 7-6 in a match riddled with rain delays.
The win was Johnson's second in two years at Wimbledon, his first coming in mixed doubles last year.
Johnson boasts a record of 41-11 for the year, claiming six titles. He is coached by UNC coach Sam Paul.
Men's Lacrosse Adds 12th Recruit
North Carolina's men's lacrosse announced Richard Thomas, a goalkeeper from the Gilman School in Baltimore, has committed to the Tar Heels.
Thomas is the fourth member of the Baltimore Sun All-Metro boys' lacrosse team to commit to North Carolina for the coming year.
The 15-man All-Metro team includes 14 seniors and one junior.
Of the 14 seniors that the team will boast this year, four will play at North Carolina.
Swimmers Finish Strong in California