Manchester City FC claimed all three points at Stamford Bridge on Thursday night, when substituteMahrez banged home a winner from a Jack Grealish cross, who was also a second-half substitute, to reduce Arsenal’s Premier League lead to a five points difference.

The 0-1 result also meant that Chelsea lost their sixth Premier League game this season, the same number as they lost the whole of last season.

Pep Guardiola’s double substitution worked well, and he joked that he was a genius. He also acknowledged that his team struggled in the first half.

“In the first half, we didn’t create much; our pressing was so poor, and we were not organized,” he said. “Everything was sloppy, we had no rhythm, and when we arrived in the position, we were not good.”

“If Arsenal had beaten Newcastle, the lead would have been 10 points; now the gap is five,” continued Guardiola. “I told the players not much has changed—there are 63 points left to play for, but there were people who believed in November that we would be champions again, and this is impossible.”

After dropping points in a 0-0 tie earlier this week against high-flying Newcastle, the last night’s victory puts City five points behind league leaders Arsenal while Chelsea are now sitting 10 points outside the top four with just one victory in their last eight league games.

Meanwhile, Mahrez became the third player in Manchester City’s history to score the most Premier League goals as a substitute.

Top of the list is former Bosnian striker Edin Dzeko, who came on as a substitute and scored 13 goals while at the club.

Former Argentinian striker Sergio Aguero (12) is the second-highest goalscorer for Manchester City as a substitute.