City's first three goals came in a devastating nine-minute spell thanks to a header from Gundogan, a Bernardo Silva volley and a long-range Sergio Aguero strike as the hosts were completely taken apart.
"We are still in February and in the Premier League we are in an fantastic position and we are nearly in the quarter-finals, we are in one final (EFL Cup) and on Monday we have the opportunity to reach the quarter-finals of the FA Cup".
Manchester City eased past FC Basel, while Tottenham Hotspur will carry a slight advantage into their second leg of their Champions League round of 16 tie after drawing away to last year's beaten finalists Juventus.
Gundogan says City can do better and he threw down the gauntlet to their Champions League rivals. He almost scored a header after two minutes, nodded City in front soon after anyway, curled in the sumptuous fourth and should have completed his hat-trick at the end. We defended quite well, we were clinical.
To the goals! And all four of them were quite nice, although Basel goalkeeper Tomas Vaclik wasn't the hero his side needed.
Brazilian Fernandinho has said that the club, who are 100% focused on each game, do not listen to the "buzz" surrounding the team.
However, they survived a scare four minutes later as Dimitri Oberlin latched onto a long ball upfield and got there ahead of the advancing Ederson, only to fire wide of the target.
City have dominated the Premier League all season and the way they have been playing in Europe shows Pep Guardiola's men have what it takes to compete with the European elite. Anyone who saw them win 4-0 at Feyenoord, 6-0 at Watford or 4-0 at Swansea City - or any number of narrower wins - will have recognised it instantly. The German was initially ruled out for seven weeks after sustaining ankle ligament damage in the FA Cup, but he's back after only 14 days.
It was also an exciting first half in Basel, with Manchester City scoring three goals before going on to win 4-0 to leave it with one foot in the quarterfinals. The Cityzens threatened on various occasions to penetrate the home side's defence, and David Silva, on as a substitute for De Bruyne, really should have added a fifth goal.
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Now 33, Ronaldo goes in for fewer 50-yard bursts of pace, but he knows exactly how to be in the right place at the right time. If ever a coach put their job on the line, it was Unai Emery heading into a must-win UCL tie.