Tottenham slip to 12th and was lucky to even escape with a 1-1 draw as Sheffield United impressed once more to move up to fifth.
The striker now leads the Premier League goalscoring charts, but with Kelechi Iheanacho never truly convincing since joining the Foxes, and Ayoze Perez playing in a wider forward position, having another attacker at the club is high up on the wish list of the King Power Stadium coach.
After early signs of promise at the start of the Spaniard's reign last season, Arsenal have now taken fewer points in Emery's first 50 Premier League games in charge than the final 50 of Arsene Wenger's 22-year tenure.
"Then you need to keep trying, keep running, and he did and gets his goal very clinically".
He added: "It was a proper Premier League game with two quality sides".
Spurs were given a fortuitous lead after halftime by Son Heung-min, but George Baldock's equaliser earned Sheffield United a 1-1 and extended their unbeaten run to five league games.
David McGoldrick thought he had levelled nearly immediately, but after a three-minute delay the goal was ruled out for Lundstram being millimetres offside in the build-up.
"The reality is that for different reasons we are not showing the performances that we expect", Tottenham manager Mauricio Pochettino said after the match.
Leicester striker Jamie Vardy has been crowned the EA SPORTS Player of the Month for October after scoring four goals in three games. "We've allowed him to do essentially what he wants to do", he said.
"Not always the most comfortable but they're winning and I think they'll keep the same side".
West Ham's misery was complete when keeper Roberto Jimenez punched Ashley Westwood's corner into his own net. "I am concerned at the easy goals we are conceding", Pellegrini, whose side have careered down the table, said.
But Richarlison struck the victor 15 minutes from time to secure Everton's first away league win since March.
Newcastle came from behind to beat Bournemouth 2-1 and Everton won 2-1 at Southampton.