Riyad Mahrez's disallowed penalty allowed Manchester City to take a significant step towards Champions League qualification with a 2-1 victory over Leicester City on Saturday.

All of the goals came in the first half at the Etihad Stadium, with David Silva's opener for the home side allowed to stand despite a strong suggestion of offside.

Gabriel Jesus's penalty increased their lead, before Shinji Okazaki pulled one back with a spectacular volley.

The oddest moment of the match, though, came in a scrappy second half, when Mahrez slipped as he converted a penalty that would have made it 2-2 and touched the ball twice.

According to the laws of the game, a penalty taker cannot touch the ball again until another player has done so, leaving referee Robert Madley with no choice but to rule out the goal.

As a result, City climbed above Liverpool to third place, edging them closer to securing a top-four berth.

City manager Pep Guardiola's decision to leave fit-again top scorer Sergio Aguero on the bench raised eyebrows, but his unchanged line-up overcame Leicester's early resistance to score twice before half-time.

Initially, it looked as if it might be a slog for Guardiola's team.

Fernandinho headed just wide from an early corner, but Jamie Vardy's pace on the break tested Nicolas Otamendi at the other end.

An unmarked Wilfred Ndidi should have done better than send a header wildly off-target from a Leicester set-piece.

City left-back Gael Clichy attracted moans from the home fans for sliding a short pass to Leroy Sane when better placed to go for goal himself following a run and cross from Raheem Sterling.

The home side did, however, break through just before the half-hour mark and in controversial circumstances.

Sane burst down the left to deliver a low ball into the middle, met by a Silva mis-hit that bobbled into the net.

Sterling, who looked to be in an offside position, swung a leg and missed the ball on its way in, causing Leicester to argue that the goal should have been ruled out.

Referee Madley refused their animated appeals and within minutes, last season's champions were 2-0 down.

Yohan Benalouane's wild sliding challenge sent Sane flying into the air and Madley pointed to the spot.

At first, it looked as if Yaya Toure, celebrating his 34th birthday, would take the kick, but he passed on the responsibility to Jesus, who sent goalkeeper Kasper Schmeichel the wrong way.

City looked set for a comfortable victory at that stage, but Leicester responded with an outstanding goal shortly before half-time.

Mahrez played a ball wide to Marc Albrighton, who swung a ball over for Okazaki to lean back and volley viciously into the top of the net with his left foot.

The second half became an increasingly physical contest, after Albrighton was caught by Fernandinho's forearm as they chased a loose ball down the touchline.

The Leicester winger was furious that the Brazilian escaped without punishment and the tone of the match became increasingly sour after that.