Man City remain first in the Premier League after they thumped Stoke City 7-2 at the weekend.
Former Barcelona and Bayern Munich manager Guardiola said his team exhausted but that he was proud of his players for holding on for a win to maintain their 100 percent record in Group F. "We made a good first half, for 30, 35 minutes, we created the two goals and could have had a third or fourth goal".
Pep Guardiola's side head into the match at the top of Group F with two wins out of two, keeping clean sheets in matches agains Feyenoord and Shakthar Donetsk. And Guardiola believes they have the quality to break Juventus's six-year strangehold on the Italian title.
Napoli had a glorious chance to pull one back 64 minutes in when, after one risky pass too many at the back, Fernandinho was caught out and Mertens took advantage by squaring for Marek Hamsik.
"This win is dedicated to them", added Guardiola.
Toronto stock market lower as Dow Jones cruises past 23000 record
Investors are also awaiting the Fed's issue of the Beige Book, a periodic snapshot on the health of the US economy. The blue-chip index had briefly surpassed the milestone on Tuesday but closed 3 points short of the record level.
The Citizens have won their last nine matches, scoring 34 times while only letting in four.
Midfielder of Turkish origin Ilkay Gundogan will have to continue waiting for his first Champions League start of the season as he also starts on the bench.
Speaking to Radio CRC in Italy, Patrick De Koster said: "In the coming months I'll meet with City to figure out how to improve and extend his contract".
"I think it was an extraordinary game from both sides".
But, don't expect a landslide by any means, on their travels this season, Napoli are averaging almost three goals a game and we expect them to at least nick a goal. "Ederson's kept us in it and we need to say a big thanks to him".