The Bees boss opted for the same XI that lined up against Frankfurt the previous weekend, with midfielder Sangaré making his Premier League debut.
Brentford started brightly in the west London sunshine. Mathias Jensen 's in-swinging free-kick, won by Kevin Schade , was flicked over the crossbar by Andy Robertson , before Lewis-Potter's fierce volley from the resulting corner was blocked by Sandro Tonali .
Jensen then robbed Lucas Bergvall , exchanged passes with Janelt and crossed for Nathan Collins , who headed wide from inside the six-yard box.
Brentford's first goal of the Premier League season arrived after 12 minutes at the end of a move of real quality.
Having taken up an advanced position, Sangaré collected the ball from Collins, played a one-two with Dango Ouattara and pulled it back for the arriving Lewis-Potter , who swept a first-time finish beyond Antonín Kinský .
Andrews' side immediately went in search of a second. Lewis-Potter's long ball was helped on by Collins and then Ajer , allowing Thiago to head against the crossbar at the far post, although the assistant's flag was raised for an earlier offside.
It was one-way traffic at the Gtech. Jensen delivered a free-kick from a central position, which Kayode glanced over the crossbar.
Thiago then peeled out to the left and delivered a low cross towards Ouattara, but the winger's heavy touch allowed Kinský to race off his line and intervene.
Brentford doubled their lead on 33 minutes. Richarlison failed to hold up the ball, allowing the Bees to seize possession inside the Spurs half.
Jensen was given time and space to wind up a shot from distance and, when Kinský could only parry his effort, Janelt tapped home the rebound.
As half-time approached, Ouattara fired over from 25 yards and then delivered a cross from the left, which Kayode headed wide.
It took Brentford less than five minutes to extend their advantage after the break with a set-piece routine perfected on the training pitches at Jersey Road .
Janelt's deep corner was met by Collins, who headed the ball into the path of Sangaré. Kinský got down well to keep out the midfielder's fierce strike, but Kayode - on his 50th Premier League appearance - was on hand to convert the rebound .
Then came Spurs' best opportunity of the afternoon. Mathys Tel released Robertson down the left and the full-back picked out Mikey Moore at the back post, but the youngster was denied from close range by Kelleher .
The Bees had a golden chance to extend their advantage on 55 minutes. Janelt's shot was blocked before Schade was pulled down by Rodrigo Bentancur , prompting the referee to point to the penalty spot. Thiago sent Kinský the wrong way, but his spot-kick rebounded off the base of the post .
At the other end, Moore was again denied by Kelleher. Mateus Fernandes swept the ball out to the right and the forward's first touch took him inside towards goal, but his stinging effort was well saved by the Brentford keeper .
Brentford then beautifully worked the ball down the right before Jaidon Anthony 's low cross was poked wide by Thiago .
Ajer nearly got in on the act when he met Damsgaard 's corner, but his near-post flick was too close to Kinský, who made a smart stop.
In the final action of the game, Callum Wilson 's shot deflected off Jan Paul van Hecke and behind, with Schade heading over from Janelt's resulting corner.
The result extended Brentford's unbeaten run in their opening home league fixture of the season to seven matches (W6 D1), stretching back to 2019.
Brentford (4-3-3):Kelleher; Kayode (Hickey 76), Ajer, Collins, Lewis-Potter; Janelt, Sangaré (Damsgaard 76), Jensen (Yarmoliuk 66); Ouattara (Anthony 66), Thiago (Wilson 83), Schade
Subs not used: Valdimarsson , Pinnock , Schuster, Henry
Tottenham Hotspur (4-3-3):Kinský; Gray ( Udogie 86), van Hecke, Senesi , Robertson; Bergvall (Bentancur HT), Tonali, Gallagher (Fernandes HT); Moore ( Maddison 67), Richarlison ( Solanke 67), Tel
Subs:Dúbravka, Danso , Davies, Williams-Barnett
Attendance:17,180
Head coach Keith Andrews shared his thoughts after Brentford began the Premier League season with a 3-0 win against Tottenham.
"I'm really pleased. There was a lot to like about how the lads performed," said Andrews.
"I really like where we are at [as a team], but nobody is going to get carried away.
"We should enjoy games like this and days like this, as they are hard earned."
Reflecting on Brentford's commanding performance, goalscorer Vitaly Janelt said the Bees' aggressive approach and positional flexibility were key to the victory.
"Straight from the off, we were very front-footed," he explained. "We tried to make it very difficult for them and I think it went very well – we punished them.
"We're all in sync and we all know what to do. Everyone can end up in different positions; sometimes I was pressing high and Mathi [Jensen] was dropping behind me.
"We adapted very well to different situations and worked very well together."
