Didier Drogba scored a lucky goal Sunday to give Premier League champion Chelsea a 1-0 victory over Arsenal and three points against one of its main title rivals.
With 17 minutes left against last season's runner-up, the Ivory Coast striker failed to control the ball in front of goal and it bounced off his shin and past Gunners' goalkeeper Jens Lehmann.
It took Drogba's tally to three goals in two games against Arsenal, coming after two efforts in the preseason Community Shield two weeks ago.
"The goal was a lucky one," Mourinho said of Sunday's matchwinner. "But this result doesn't make a champion or doesn't decide that the loser cannot be champion. It is just one game. We have dozens and dozens of matches to play.
"There's no reason for Arsenal to feel after this game that they cannot win [the title]. But I would love them not to do it and to give up now."
Chelsea's second 1-0 shutout means that Mourinho's team is level on points in the standings after two rounds with Tottenham, Charlton and Manchester United. Tottenham is top on goal difference.
After a win and a loss, the Gunners now have three points to make up.
"We feel we gave a very, very cheap goal away," Wenger said. "We basically gave the game away."
But the Arsenal coach was more worried about his team's self belief, usually its strong point.
"I feel the whole level of the game was not satisfying for me. I expected a much better game. We lacked a fraction of belief," he said.
"I hope the team goes home very frustrated. I hope that their disappointment is so strong and there is a realization that we can do much better and that there is more belief than that."
In Sunday's other game, Everton posted a 1-0 victory at Bolton to recover from last weekend's 2-0 home loss to Manchester United. Marcus Bent scored the only goal in the 52nd minute.
The early season showdown at Stamford Bridge was a letdown as enterprising play was stifled by a crowded midfield and creative players such as Frank Lampard, Thierry Henry and Cesc Fabregas struggled.
Chelsea almost went ahead in the second minute when John Terry headed a corner kick towards goal. Lehmann got a hand to the ball and Fredrik Ljungberg cleared it off the line.
Chelsea made a change at halftime, sending on Drogba for Hernan Crespo, who had few chances to follow up last weekend's 25-yard strike against Wigan.