My first "pro-event" was Reno a number of years ago. I was extrememly nervous, and could not get to sleep at night because I was so anxious. When the matches started, I actually got the "shakes", and missed a relatively easy shot immediately. As I sat down and watched my opponent run out, I realized that I could have done that and I determined that I would concentrate on simply making each shot that I was presented with. My mantra was "one shot at a time". Try and be indifferent to missed shots, just do your best when presented with an opportunity at the table.
At any rate, I surprised myself and won my first two matches. The first player was an "unknown", but he played very well. The 2nd player, was Richard Grenier (an excellent and well regarded one pocket player). I actually played damn near perfect against Richard and ended up victorious by something like 9 to 3. To this day, I actually remember some of the runouts because I was so mentally focused on that match.
My next match was against Troy Frank, and I was very confident having gambled against him in the past. I was most certainly an underdog, but felt that I had a chance based on my last performance. Wrong. I ran the first rack, and then basically sat while he ran out the set. What few opportunities I did have were ruined because I let his terrific play get to me. I lost sight of the "one ball at a time mantra" that I had in my previous matches. I made really dumb mental mistakes.
My last match was against a pro who's name I can't seem to recall right now. I lost something like 9 to 6, but I remember that the match could have gone either way. After losing, I watched John Schmidt lose 9 to 0 against Max Eberle. The moral to the story is that great players don't always play well in every match.
My long winded advice is play every ball with the same care and intensity regardless of the score. Also, play smart, if you don't feel pretty darn confident of making a shot....play safe.
Enjoy,
Doug