The runner-up in stroke-play qualifying for the tournament, Mickleson won the final hole with a par 4.
Mickelsons putter saved him down the stretch. He made a 7-footer to win the par-4 16th hole and square the match, a 15-footer on 17 to stay tied with Kammann and a 5-footer on the 18th hole to win.
The men's golf coach at the University of San Diego, Mickelson said he and Kammann, of Baneberry, Tenn., both played well despite an all-day drizzle.
Im not a big fan of playing in the rain. In those conditions I thought I played pretty good, Mickelson said.
Stroke play medalist Richard Berkmeyer defeated Dan Horner 3 and 2 in his opening match.
The St. Louis native played well for two days to top 264 golfers with a 2-under par 138 total after 36 holes of qualifying ' one stroke better than Mickelson. But he said his game deteriorated on the first day of match play and he struggled to win.
Berkmeyer never trailed after winning the fourth hole with a par 3. Horner, of Sandy, Utah, won the 13th and 14th hole to trim Berkmeyers lead to one hole but he took the next two holes to close out the match.
Jordan Byrd of Columbia, S. C., the assistant golf coach at Clemson, defeated Ron Ewing, 3 and 2.
Two former Mid-Amateur champions were eliminated. Austin Eaton III (2004) lost to Gene Elliott, 6 and 4; and Tim Jackson (1994, 2001) fell to Andrew Davis, Chicago, 1-up.