Getting Unlucky Against One Guy

Have you ever noticed how you can run a table but just be owned by one player? In the Tuesday Moose tournament that happened to me. With only 11 players, I had about 1/3 of the chips with 5 players remaining. The short stack was all-in with 1,000 at 500/1000 blind level and I picked up A/J two under the gun. I raised all-in to isolate him and he turned over....A/3. Naturally, a 3-outer 3 came on the flop and he now had 2500. The very next hand, under the gun, I have pocket Jacks. I raise all-in and the same player (with only 500 invested), calls with...8/9 offsuit! The flop has a 7, the turn a 6, and the river.....you guessed it a 10 for the runner-runner straight. This player managed to donk off "my" 5000 chips on the next hand to another player with his flush draw!!!! P.S. Got knocked out in 4th place.