The England defender scored a late goal to help the Foxes run out 2-1 winners at Southampton on Saturday.
Claude Puel's charges now boast two wins from three league games so far, prompting Maguire to talk up his side's domestic prospects.
"We've got a great spirit amongst the lads," the 25-year-old told the Leicester website. "We've got an ambitious squad, we want to push on as high as we can.
"We weren't really happy with our first-half performance. We felt like they were dominating the game. The second half was a lot more like ourselves. We played with much more tempo.
"We created chance after chance and there only looked like one team that was going to win the game and thankfully I got the goal and we take the three points back. A last-minute winner in front of the away fans - there's nothing better."
Maguire was linked with Manchester United over the summer thanks to his impressive displays for club and country over the past few months but no move materialised.