What happened: A fifth-set tiebreak between Carlos Alcaraz and Ben Shelton pushed a US Open match into the early morning, with the finish landing around 3:21 a.m. ET. The late finish prompted fans and observers to question why the match wasn't scheduled earlier in the night session.

Why it matters: Night-session start times at the US Open have drawn recurring complaints when marquee matches run long, leaving fans and West Coast or international viewers unable to watch live. Reaction to this match reopened that debate, with some calling the scheduling a disservice to a high-profile matchup.

What to watch: Whether the US Open adjusts night-session scheduling for remaining marquee matchups will be the next thing to watch.