Leyton Orient began life in League One with a slender loss in their London derby after a battling display at The Valley.

Richie Wellens named new signings Sol Brynn and Joe Pigott in his starting line-up, with fellow summer arrivals Ethan Galbraith, Jordan Graham and Sam Howes among the substitutes.

And after both sides observed a minutes applause for the late Chris Bart-Williams, the visitors saw Ruel Sotiriou have the first attempt at goal on two minutes.

Brynn made a superb save to deny Alfie May moments later, while Pigott was brought down by home keeper Ashley Maynard-Brewer but denied a penalty by an offside flag.

Sotiriou had a shot blocked on seven minutes, while a Tom James free-kick was nodded down by Omar Beckles for Pigott, who was unable to get a shot away.

But Beckles was then booked for bringing down Tyreece Campbell, with May sending his free-kick just past the top corner. And Idris El Mizouni was shown a yellow card for a foul on George Dobson moments later.

Maynard-Brewer pushed Theo Archibald's low effort away just before the half-hour mark, while Karoy Anderson escaped a caution afer fouling Beckles and Terell Thomas also avoided a booking when hauling down Archibald. 

James fired a free-kick over the crossbar, but Charlton got their noses in front just before the end of the first half when George Dobson struck from close range after good work by Corey Blackett-Taylor.

May was booked for dissent soon after the restart, with Pigott seeing a header from a corner blocked by Lucas Ness on 52 minutes and James having a shot deflected just over the crossbar shortly before the hour mark.

Charlton's Scott Fraser was then shown a yellow card, with teammate Nathan Asiimwe dragging a shot wide from outside the area.

But O's then enjoyed a good spell midway through the half and El Mizouni had a shot saved by Maynard-Brewer.

Wellens made his first change of the day with 19 minutes left as Pigott made way for George Moncur, with Scott Fraser firing just over for the home side soon after.

And O's made a triple switch with 11 minutes to play, as Galbraith, Graham and Jordan Brown relieved Darren Pratley, Rob Hunt and James.

Brynn raced off his line to deny May a chance on 84 minutes, while El Mizouni made a timely intervention to thwart Charlie Kirk as he looked set to score.

Charlie Pegrum was sent on for his league debut in the first of seven minutes of stoppage time, as Maynard-Brewer was booked for time wasting.

But O's had a let-off when Camara shot wide after Brynn had made an initial save in the third minute of injury time

Pegrum went close to an equaliser, but was denied by Maynard-Brewer before Graham was fouled on the edge of the box.

Brynn made his way upfield for the free-kick, but O's could not force a last-gasp leveller.

Leyton Orient: Brynn, James (Brown 79), Sweeney, Happe, Pigott (Moncur 71), Sotiriou, Archibald (Pegrum 90), El Mizouni, Pratley (Galbraith 79), Beckles, Hunt (Graham 79). Unused subs: Howes, Turns.

Attendance: 18,512 (including 3,153 Orient fans).