The U.S. Open lets fans in free the week before the tournament to watch qualifying matches for those on the professional fringes.
World number one Williams, a 16-time Grand Slam winner seeking her fifth US Open crown and her ninth title of the year, dispatched 18th seed Carla Suarez Navarro 6-0, 6-0, in 52 minutes on the Spaniard's 25th birthday.
Makarova had lost all three previous matches she'd played against Radwanska in straight sets. The Russian's victory Sunday allowed her to reach her third Grand Slam quarterfinal
Andy Murray, a dedicated fan of night sessions in New York where the atmosphere usually becomes more raucous as the consumption of alcohol increases, said he had no fear that he would end up playing his first round on Thursday.
He was a break to the good for 2-1 against serve-and-volleyer Llodra in the decider and went to match point after getting the better of a rally which started with his left-handed opponent sending over a cunning under-armed serve. Andy Murray hit 34 winners against just five unforced errors while Michael Llodra committed 29 unforced errors.
The 2011 champion rallied from a break down in the final set on Saturday to beat Ekaterina Makarova of Russia 6-3, 2-6, 6-3 and reach the fourth round.
Playing on Court 14, Llodra lost the first set of his second round singles match 7-5 to Italian 23rd seed Andreas Seppi, then pulled out due to what he said was a hamstring tear. So, many people were surprised when three hours later he turned up on Court 6 for a match with his doubles partner Nicolas Mahut.
Frenchmen Michael Llodra and Paul-Henri Mathieu have joined seven players who pulled out on Wednesday.
France's Michael Llodra retired from his second round Wimbledon match with Italian 23rd seed Andreas Seppi on Thursday, taking the total of pullouts to 11 at the tournament.
He is making his 13th appearance at the pre-Wimbledon warm-up and took the title for the first time in 2012, beating Roger Federer in the final.