Ronald Koeman believes the sending off of Idrissa Gana Gueye was a match-defining moment as Everton lost 5-2 against Arsenal at Goodison Park.
Wayne Rooney’s 12th-minute strike - a wonderful effort that evoked memories of his first senior goal for the Blues against the Gunners in 2002 - gave the hosts the lead.
But Arsenal ensured they would go in level at the interval after Nacho Monreal pounced on a rebound after Jordan Pickford had initially saved Granit Xhaka’s deflected low drive.
Koeman shuffled his pack at half-time, opting to replace Ashley Williams with Tom Davies in a bid to dampen the threat of Arsenal’s vibrant attack.
But, after an equal opening to the second period, Mesut Ozil headed in Alexis Sanchez’s pinpoint cross to put Arsene Wenger’s side in front for the first time.
Then came the sending off of Gana for a second bookable offence - and the visitors subsequently stretched their lead to 4-1 following strikes from Alexandre Lacazette and Aaron Ramsey.
There was still time for two more goals in second half added time, however, as substitute Oumar Niasse temporarily reduced the deficit before Sanchez hit back with his second of the afternoon in the dying seconds.
“It was difficult,” Koeman told evertontv afterwards. “The start was okay - it was a great goal by Wayne, but already from the start we had some difficulties to stop Sanchez. He had a big impact today in moving between the lines and we had difficulty stopping that.
“It was 1-1 at half time and we changed to have four at the back to have a little bit more control in the midfield. The first 10 minutes after half time was okay and we had a good chance.
“They took a good chance from a counter-attack to make it 1-2. Then there was the sending off of Gana - and that makes it really difficult, it was already difficult 11 against 11 but even more difficult, impossible at 10 against 11.”
Despite the defeat, Koeman insists he remains positive as he bids to turn around Everton’s fortunes.
He added: “It’s about how you look at this situation - if you start to think negatively then maybe there is no solution but I am not like that.
“There’s rumours in the newspapers but it is normal. I mentioned on Friday that it is normal, because the team is under-performing, the team is in a difficult situation. Mentally, confidence-wise, the team is struggling and that is what we need to change.
“Personally, I still believe that I can change the whole situation.”