"Phil is incredibly talented but we have to handle him in the right moment," Guardiola said. "We needed his capacity to press high. He's a guy who has the quality to arrive in the box. I trust a lot in him."
Bernardo Silva was the architect of the goal, sending in a cross that Sergio Aguero nodded across the face of goal and Foden directed a powerful diving header into the net.
"It just felt it's everything I have been working for since I was a kid," Foden said.
The immediate priority for City is wrapping up a treble by defending the Premier League and beating Watford in next month's FA Cup final, having already collected the League Cup.
City's quest for a first European Cup was ended by Tottenham, who lost 4-3 at the Etihad Stadium on Thursday but advanced on away goals with a 4-4 aggregate score.
Tottenham's priority before hosting Ajax in their Champions League semifinal next Wednesday is fortifying their place in the Premier League's top four to ensure a place in Europe's elite competition next season without having to win it.
"It is in our hands to be in the Champions League next season," said Tottenham manager Mauricio Pochettino after his side's fifth successive away league loss. "Now it's about trying to be strong and recovering the energy."
Elsewhere, Ayoze Perez's hat-trick all but guaranteed that Newcastle will remain in the Premier League next season after securing a 3-1 victory over Southampton.
Newcastle are 10 points clear of Cardiff in the relegation zone after a sixth win in their last seven home league games.
The tougher challenge for Newcastle could be keeping manager Rafa Benitez, who wants investment in the squad.
"Right now, you see our position and we are not competing," Benitez said. "We have to compete."
Gerard Deulofeu scored twice to give Watford a 2-1 win at already relegated Huddersfield, keeping the seventh-placed side on course for their highest Premier League finish.
Brighton frustrated Wolverhampton Wanderers in a 0-0 draw to gain a key point in their scrap with Cardiff to avoid relegation. Brighton are three points ahead of Cardiff, who occupy the final relegation place and hosted Liverpool overnight.
Fulham, who have also already been relegated, clinched a 1-0 victory at Bournemouth, their first away win of the season, while Leicester twice came from behind to hold West Ham to a 2-2 draw, with Harvey Barnes equalising in the 92nd minute.
- AP