Arsenal survived a scare to beat Crystal Palace 2-0 on Saturday, with a Mikel Arteta penalty and an Olivier Giroud header maintaining their lead in the Premier League.
Yet Arsene Wenger will know it could easily have been different after Arteta was sent off with 25 minutes still remaining at Selhurst Park against managerless Palace.
Wojciech Szczesny produced two brilliant saves in the space of a minute to deny the hosts an equaliser in a spirited display just days after manager Ian Holloway left Palace by mutual consent.
However, it was Arsenal who made it seven wins from their last eight Premier League matches to leave Palace in deep trouble in the relegation zone.
After losing their first match since the opening day of the season against Borussia Dortmund in mid-week, manager Arsene Wenger named a strong side but left Jack Wilshere on the bench following his slight knock in that game.
Mathieu Flamini returned to take his place in midfield, but the Frenchman only lasted seven minutes before limping off, with winger Serge Gnabry coming on to take his place.
By then, Giroud had already headed over a good cross from Bacary Sagna as Arsenal completely dominated possession.
The reshuffle allowed Palace to find their feet, with caretaker manager Keith Millen having made six changes from the side that lost 4-1 to Fulham on Monday in Holloway's final match in charge.
Marouane Chamakh and Jerome Thomas were each handed the opportunity to prove a point to their former club in a defensive 4-5-1 formation that suggested Palace would be happy with a draw.
A burst of pace in the 14th minute from Thomas left Sagna for dead, but Barry Bannan could only direct his header over the bar.
Three minutes later, Mesut Ozil should have given Arsenal the lead after being played in by Aaron Ramsey, but opted to cut the ball back across the face of goal rather than shoot.
Lifted by the home crowd, Palace's confidence seemed to grow and both Mile Jedinak and Adlene Guedioura had efforts from distance that tested visiting goalkeeper Szczesny.
Scotland midfielder Bannan spurned an even better opportunity after Arsenal failed to clear a free-kick, with his curler just missing the target.
At the other end, Santi Cazorla almost found a way through, but his cross-shot eluded a queue of players waiting in the six-yard box, while Ramsey worked Palace goalkeeper Julian Speroni from a similarly tight angle.
Chamakh then had a glorious opportunity to score against his old club just before the break, only to mistime his jump and completely miss the ball.
But having worked so hard in the first half, all of Palace's efforts were washed away inside the opening 60 seconds after the break.
Guedioura's rash decision to slide in on Gnabry inside the box handed Arteta an opportunity from the spot and he made no mistake to put Arsenal ahead.
Giroud should have put them further ahead eight minutes later after good work down the right from Sagna, but connected with shoulder instead of head and missed the target.
Within minutes of that miss, Palace were handed a lifeline after referee Chris Foy showed Arteta a red card for bringing down Chamakh as he raced through on goal.
It looked a harsh decision given that Ramsey was covering, but it forced Arsenal into another reshuffle as Wilshere came on for Gnabry.
They had Szczesny to thank for keeping them in front. First Joel Ward saw his powerful shot tipped onto the bar and from the resulting corner, the Polish keeper produced an even better stop to repel Jedinak's swirling volley.
Giroud had the simple task of finishing off Ramsey's chipped cross to seal the points three minutes from time with his fifth league goal of the season.