A few LCC ones but one T/A I was very close.
Flying PHX-DFW-LON and booked the 1st sector to give me a couple of hours in DFW, course the 1st sector flight was delayed by couple of hours so ended up running like hell through Terminal, staff had already finished all checks and door had just been shut. They looked and asked me are you X and which poiint in time produced ticket and passport, door open and got on board, crew already standing to do safety briefings.
Someone had pinched allocated seat and F/A was asking him to move but as I saw flight was half full with lots of seats I told guy to stay where he was as he looked comfortable and I will find another seat.
F/A on final checks stopped and said thanks for not making an issue as pax in my allocated seat had been difficult earlier and he would have started again, did get looked after well on the flight though.