Manchester City took a giant step towards the Champions League quarter-finals as they comfortably beat Basel at St Jakob-Park.
Pep Guardiola's side took command of the last-16 first-leg tie within half an hour in Switzerland as Ilkay Gundogan, Bernardo Silva and Sergio Aguero all scored within a nine-minute period.
Gundogan put City in front on 14 minutes, heading in Kevin de Bruyne's corner at the near post.
Four minutes later Silva doubled the lead, cushioning Raheem Sterling's cross on his chest before firing a volley at Basel keeper Tomas Vaclik, who could only tip the ball into his own net.
Aguero then scored his 29th of the season and his 198th for City in the 23rd minute, whipping a right-footed shot into the bottom corner from 20 yards with Vaclik rooted to the spot.
Gundogan curled City's fourth into the top corner 10 minutes after the break and was denied a hat-trick by Vaclik, who saved the German's shot from close range.
The return leg at the Etihad on 7 March should be routine for City, who lead the Premier League by 16 points and face Arsenal in the Carabao Cup final.
Basel waste chances
City enjoyed almost 74% possession against the reigning Swiss Super League champions and they made a mammoth 868 passes in the game, compared to Basel's 294.
The visitors were relentless in attack and the scoreline reflected an imperious performance by Guardiola's side.
But Basel were able to get at the heart of the City defence on a number of occasions.
It was the home side who threatened first with striker Dimitri Oberlin squandering an excellent chance on a counter-attack with only the onrushing keeper Ederson to beat.
Valentin Stocker saw his shot blocked when also through against Ederson, while the Brazilian keeper had to make a finger-tip stop to deny Mohamed Elyounoussi from long range.
The chances kept coming for Oberlin in the second half as he missed a close-range header and saw a free-kick saved by Ederson.
City show strength in depth
At the beginning of February, Guardiola was lamenting City's injury list and he only named six substitutes for the 1-1 draw at Burnley.
But his bench in Basel showed that the injury crisis is nearing an end as both Leroy Sane and David Silva were named as substitutes.
With the game won, Guardiola was able to give valuable game time to that pair and rest his other stars.
Sane, who had initially been ruled out for six weeks with an ankle injury sustained in City's FA Cup win over Cardiff on 28 January, came on for Sterling, while Silva made his return from a hip injury as a 62nd-minute replacement for De Bruyne.
In defence, Fabian Delph returned to left-back after missing the last six games with a knee injury, while captain Vincent Kompany played his first Champions League game since May 2016.
This strength in depth will be crucial as the Premier League leaders continue to chase a historic quadruple.
Man of the match - Ilkay Gundogan
'Gundogan is an extraordinary player'
Manchester City boss Pep Guardiola on BT Sport: "An excellent result. We are almost in the quarter-finals. Champions League is always 180 minutes and we will take the game seriously but it's an excellent result.
"Ilkay Gundogan is an extraordinary player. Last season we missed him a lot with an injury for six months and that's why we are so satisfied, not just the quality but personality to play.
"We are still in February and in the Premier League we are in an amazing position and we are almost in the quarter-finals, we are in one final (Carabao Cup) and on Monday we have the opportunity to reach the quarter-finals of the FA Cup."
Unbeatable Silva & City better last season's tally - the stats
- David Silva's substitute appearance means he has now played more games in all competitions this season than any other player across the top five European Leagues without suffering a single defeat (28 games and no defeats).
- Since the turn of the year Aguero has scored 14 goals in 11 matches - no player has netted as many across the top five European Leagues in 2018.
- City have now won 16 of their 21 away matches in all competitions this season, a joint-high across the top five European Leagues matched only by Paris St-Germain.
- City have won 34 of their 41 matches in all competitions in this campaign, more than in the entirety of last season (won 33 of their 56 games in all competitions during 2016-17).
- The 4-0 victory over Basel is the biggest away win by an English side in the knockout stage of the Champions League
City travel to League One side Wigan in the FA Cup fifth-round on Monday (19:55 GMT), before a trip to Wembley on 25 February to play Arsenal in the Carabao Cup final as Guardiola looks to pick up his first trophy at the club.