Manchester City remain firm favourites to be Premier League champions after a curate’s egg of a contest in which Riyad Mahrez starred yet slipshod defending from the home team and Southampton was at fault for all seven goals. Jonathan Moss and VAR had a particularly disappointing night, the referee and technology each failing to award a clear penalty when Alex McCarthy downed Phil Foden in the area when the score was 1-1. Ultimately City did not care, as they ran out clear victors due to Mahrez’s display, which was supported by Foden and Kevin De Bruyne, each of whom were relentless. Pep Guardiola’s side are 14 points ahead of Manchester United, meaning 17 are required from their last nine games to seal the title. It may well be fewer as this calculation hinges on United winning all of their last 10 matches: this would take them to 84 points, two less than the tally six victories will give City. The manager was pleased with this response to the defeat against United on Sunday, and his team now move on to Fulham on Saturday. Win there and City’s lead will be 17 points, having played two games more than their crosstown rivals, who host West Ham on Sunday. Southampton began strongly, most of their joy coming along the left where Mohammed Salisu posed questions. Stuart Armstrong drove along a central channel and City could not prevent a pass to the No 22 before, eventually, they scrambled clear. After Armstrong won an opening corner off Oleksandr Zinchenko, the roving left-back again troubled Guardiola’s men along their right. Here, slick Kyle Walker footwork was required for the ball to be worked to Ederson, who hoofed away. This was encouraging for Southampton but City pounced via a sweeping move in which Walker passed to Rúben Dias who from near halfway pinged the ball into Zinchenko, whose run along the left caught the visitors slumbering. The defender’s cross was hit first-time by Foden and, when McCarthy parried, De Bruyne finished. Southampton were disheartened; City’s rhythm and confidence elevated. They tapped the ball around with ease but, then, Walker and Aymeric Laporte contrived to hurt them. First the former’s backheel ceded the ball – to Guardiola’s disgust – and suddenly Nathan Redmond was surging at Ederson, the forward forcing a corner. Then came Laporte’s error: Jannik Vestergaard headed James Ward-Prowse’s delivery at City’s No 1, who saved, and when the Dane lunged for the rebound the Frenchman yanked him over. Moss awarded a penalty, VAR vindicated the official, and Ward-Prowse beat Ederson via the centre of his goal. This seemed as clear a decision as one that Moss and VAR were about to turn down. After McCarthy miscontrolled a Salisu back-pass, Foden was cleared felled by the goalkeeper. Yet VAR refused to overturn Moss’s judgment that this was not a spot-kick, much to the deep and understandable outrage of Guardiola and his bench. City were stunned and nearly conceded before clearing their heads. Ederson barely saved a long-range Ward-Prowse effort, then Moussa Djenepo was clear but missed, badly, to the keeper’s right. Yet justice was served as City entered the break ahead. Oddly Che Adams, Southampton’s centre-forward, was in a right-back position from where he passed straight to Mahrez: the Algerian was 25 yards out yet his finish, to McCarthy’s right, was pinpoint. City next administered a close-to-knockout blow with a third on the stroke of half-time. Mahrez’s feet bamboozled Saints but they were too slow, allowing his attempt to trickle back off McCarthy’s right post to Ilkay Gündogan, whose close-range finish was simple. City had Southampton under their spell, Bernardo Silva and Foden each going close to adding a fourth. As if a string was attached to the ball, Saints could not stop their opponent pulling it around them. Thus there was scant surprise when Foden fed Mahrez and more dazzling feet from the virtuoso Algerian presaged another strike in the corner – again Saints had sleepwalked. Yet the scoreline was 4-2 moments later when more lax concentration – this time from Silva – gave Nathan Redmond the ball and his backheel was hammered home by Adams. De Bruyne’s killer instinct, though, restored City’s three-goal advantage when beating McCarthy after Southampton again switched off and that was contest over. By the close Sergio Agüero had been given 16 minutes: if City’s record scorer can return to top form this will be a further bonus.