Raheem Sterling scored the quickest goal of the Premier League season at 38 seconds to set Manchester City on its way to a 3-1 win over Watford that moved the leaders 15 points clear on Tuesday.
Christian Kabasele scored an own goal and Sergio Aguero added a third as City bounced back from dropping points for only the second time this season — in a 0-0 draw at Crystal Palace on Sunday.
Andre Gray scored a consolation goal for Watford in the 82nd minute, just as City was about to go six hours without conceding.
Guardiola fielded his strongest possible lineup at Etihad Stadium, taking no chances after the slip-up against Palace two days earlier and with a trip to Liverpool up next in the league.
City beat Watford 6-0 and 5-0 in their two previous meetings and it threatened to be a similar thrashing from the moment Sterling hooked in from close range following Leroy Sane's fierce center across the face of the six-yard box.
Kevin De Bruyne, who made a quick recovery from what appeared to be a serious-looking leg injury near the end of the Palace match, surprisingly started and provided the cross that was turned into his own net by Kabasele in the 13th minute.
Aguero missed two chances before halftime, and another soon after the break. But the Argentina striker got his 13th league goal of the season when he prodded in from close range after Watford goalkeeper Heurelho Gomes fumbled a cross from De Bruyne.
That was Aguero's sixth goal in his last three games against Watford, against whom he scored a hat trick away this season.
Gray was denied by a superb diving save from City goalkeeper Ederson Moraes late in the first half but was faced with an empty net when Andre Carrillo crossed from the left after bursting clear. Gray couldn't miss.
The draw against Palace ended City's record 18-match winning run.