The England winger, or 'Raz' as Pep Guardiola calls him, has had a rough few months but he looks a different player on the right-hand side for the Blues
If Manchester City's Premier League opener provided evidence of slow progress under Pep Guardiola, Tuesday's Champions League play-off victory was much more like it.
City did just about enough to squeeze past Sunderland at the weekend. There were signs of Guardiola's influence - most notably the full-backs coming into central midfield - but things did not quite click, which is to be expected at this stage of the Catalan's reign.
Their dismantling of Steaua Bucharest, though, was far more impressive. The passing was more crisp, the movement looked more fluid and the chances flowed. It must be said that the opposition were far less dogged than the Black Cats, but City thrived in the space they were afforded.
Sergio Aguero missed two first-half penalties but, incredibly, he scored a hat-trick anyway.
His first, City's second of the night, was laid on beautifully by Raheem Sterling. The man pilloried by sections of the British press (though, it must be said, usually not the sports sections) during and after the European Championship showed why City paid upwards of £45 million for him a year ago.
It is said Guardiola gave that move the go-ahead last summer, several months before his move to the Etihad Stadium was confirmed.
The boss admits he, as well as his backroom team, had been won over by "Raz" - as he calls him - long before he was thinking about a move to Manchester.
"He can play right and left, he can go byline or go inside, and that is so important," Guardiola said on Saturday after Sterling had impressed. "He is a fighter and of course we want more of him, but we are so so happy.
"We are happy for him because he's a very nice guy, and from the beginning I had a feeling - maybe it will be a mistake, maybe for the rest of the season Raz is not going to play good - but from the beginning I had that feeling that this guy is good.
"I saw many times in England, when playing Liverpool, I said, 'Wow this guy is good'. Not just me, all the staff, all the physios, and my assistant, wanted to have him, wanted to have him to see the real Sterling."
The real Sterling, City fans will be increasingly hopeful, is the one we are seeing now, rather than the young man who struggled at the back end of last season and carried those problems into the Euros.
Things got so bad for Sterling in France that Guardiola called him personally in a bid to keep his spirits up. There was no immediate improvement, even if he did produce a fine run to win England's penalty in that fateful game against Iceland, but he looks much better now.
Indeed, he's won two more penalties already this season. He also picked up two impressive assists; before teeing up Aguero, he set up City's opener in Romania, turning his marker inside out before cutting it back to David Silva.
Sterling had been used in a variety of roles by Brendan Rodgers at Liverpool but it seems the right-hand side could become his home under Guardiola. Nobody would have seen it, but the Catalan was said to be impressed by the Englishman's performance there in a behind-closed-doors friendly against St Johnstone. He has played there ever since.
He started last season in fine form, of course, but his campaign petered out along with most of his team-mates. The atmosphere at City these days is increasingly positive.
There are signs that the players are tuning in to Guardiola's wave length. John Stones, in his second appearance, was imperious at the back. He was signed because of his penetrative passing and it was on display here on numerous occasions.
Kevin De Bruyne looked lost at the weekend but there was a marked improvement against Steaua, Silva looked something like his old self in a more advanced role, and Nolito picked up his first goal for the club.
Claudio Bravo will be another piece of the puzzle when he joins from Barcelona.
