BIRMINGHAM, England -- Danny Drinkwater has seen Riyad Mahrez make fools of his opponents countless times, but this was the first time the opponent in question was him.

Having been Mahrez's teammate for four years at Leicester City, during which the pair played pivotal roles in the club's fairytale Premier League title triumph of 2016, Drinkwater will have known exactly what was coming when the Algerian powered towards him in the 18th minute of Sunday's game at Villa Park. Yet with a trademark dip of the shoulder, Mahrez stole past his former colleague before planting a low shot into the bottom-right corner to open the scoring of Manchester City's 6-1 rout of Aston Villa. In a manner that reflected the stark way in which their fortunes have diverged since they parted ways at Leicester, Drinkwater got no closer to his former colleague all afternoon.

If the blame could be shared for Mahrez's opener, Drinkwater was almost solely responsible for the City winger's second goal, six minutes later, when he was caught on the ball inside his own box by David Silva and his former sparring partner smashed home. He did not cover himself in glory for the visitors' third either, shortly before the half-hour mark, tamely nibbling at Kevin De Bruyne's heels and allowing the Belgian to tee up Sergio Aguero for a zinging shot that flew into the top-left corner from just outside the box.

After Gabriel Jesus added a fourth, gloriously created by De Bruyne, Aguero went on to complete his hat trick with the visitors' fifth and sixth goals. It gave him the outright record for hat tricks in the Premier League era (12) and increased his career tally of goals in the competition to 177, which took him past Thierry Henry as the top-scoring non-English player in the English top flight during the same period. Mahrez had a hand in Aguero's hat-trick goal as well, punishing Kortney Hause's weary pass with a first-time ball into the Argentine, who rifled a shot past Villa goalkeeper Orjan Nyland.

Drinkwater had left the fray by then, his Villa debut having come to an unceremonious end in the 79th minute. They were the first minutes that he and Mahrez had spent on the pitch together in the Premier League since their final match in Leicester's colours against Watford in May 2017.

Both players had hoped to leave the King Power Stadium that summer, but it was only Drinkwater whose wish was granted, with Mahrez obliged to spend one last season in the East Midlands while his colleague headed to Chelsea. Drinkwater appeared sporadically in his maiden campaign at Stamford Bridge under Antonio Conte, before disappearing from view entirely when Maurizio Sarri arrived at Chelsea in the summer of 2018. Used just as sparingly at Burnley in the first half of the current campaign, this was only his second Premier League start since March 2018.

Unfortunately for Drinkwater, each of his past three league starts -- for Chelsea, Burnley and now Villa -- has come against Pep Guardiola's City. The 29-year-old, signed on loan to provide cover for the injured John McGinn, can at least console himself that he will not have to face the defending champions again in the league this season, although they could yet meet Pep Guardiola's men in the Carabao Cup final.

While he accepted that Drinkwater had been at fault for City's second goal, Smith defended his decision to throw his new recruit straight into his starting XI. "Danny Drinkwater will make us a better team," said the Villa manager, whose team at least grabbed a consolation through auxiliary striker Anwar El-Ghazi's stoppage-time penalty.

There were moments last season when Mahrez's post-Leicester career looked to be in danger of heading in the same direction as Drinkwater's, as he struggled to impose himself at the Etihad Stadium, but he has come into his own in recent weeks and his performance at Villa Park left Guardiola beaming.

Mahrez has already made 12 league starts this season, compared with 14 across the whole of last term, and his tally of 22 goal involvements (nine goals, 13 assists) is bettered at City by only De Bruyne (24) and Raheem Sterling (26). After a difficult spell between early November and early December, during which City won only twice in seven outings in all competitions, Mahrez has played a central role in their recent upturn, starting each game of their current five-match winning streak -- with the exception of the 4-1 FA Cup victory over Port Vale -- providing three goals and three assists.

"The difference between last season and this season is that he plays more minutes because the manager is so kind to him," Guardiola said with a smile. "But the level he played last season was good too. He loves to play football, has incredible quality. You see his legs, it's impossible [for him] to be injured, because he has no muscles. In the final third he has something special. You always have the feeling he can score a goal."

After recent tactical innovations including a switch to a back three and a fluid striker-less system for the mid-week Carabao Cup semi-final first-leg win over Manchester United, Guardiola reverted to a more conventional 4-3-3 formation for the trip to Villa, although he did permit himself the novelty of pairing Aguero and Jesus at kick-off for the first time in the league since Sept. 2018.

Regardless of the team's set-up, when Mahrez is in this kind of mood, City can be impossible to stop. Just ask his old pal Danny Drinkwater.