Luke Cowan-Dickie's hat-trick ensured Exeter director of rugby Rob Baxter was able to reflect on his club's first win of the Aviva Premiership season.
Last season's finalists had lost their opening two matches but shot out to a 34-13 lead after 50 minutes in a five-try rout.
Baxter had some reason to grumble, after Harlequins battled back, but overall was pleased with a performance that gets Exeter's campaign up and running.
"We have been under a bit of pressure after two losses but it was fantastic to win and get a bonus point as well," Baxter said.
"We did enough and scored some good tries but we are frustrated by our second-half performance. We should have controlled territory a bit better than we did but I am pleased with the character shown by us.
"We were far from being at our best but I am not that upset that Quins came back into it. They are a successful Premiership side and they have got some dangerous players, who can score some good tries."
Exeter became very disjointed in the final quarter with a raft of substitutions resulting in a lack of fluidity in their play.
Their cause was not helped by the loss of Tomas Francis, their replacement prop, who was sent off for illegal use of the boot with eight minutes remaining.
Baxter had no issue with the referee's decision, saying: " I can't deny that we were told before the season started that if you flash a foot in a ruck and connect with a person's head then a red card may follow.
"Tomas's shin appeared to catch Danny Care on the back of the head.
"It was a difficult decision in relation to the use of replacements but I was looking ahead of the game next week. We have a game on Friday (at Bristol) and it is about the overall management of the squad and getting them to tick over."
Cowan-Dickie was Exeter's hero by scoring a hat-trick of tries to add to the one he scored against Saracens last Sunday. Baxter was full of praise for his promising hooker.
"Luke is playing flat out, he is bang on form and hopefully he can take that form into the Autumn Internationals," he said.
Quins' boss John Kingston accepted that simple errors had cost his side any chance of victory.
"We gave away two soft tries in the middle of the first half when we were 6-5 up," he said.
"One of them was a simple overthrow and the second came from poor tackling from the first phase.
"It was very difficult to come back from there and we didn't start the second half as well as we would have wanted. It was a question of too little, too late and the bottom line is that we were punished for too many errors at key points.
"We have to alienate those errors, and it is not about work ethic, but Exeter did take every opportunity that came their way."
Next up for the Quins is a home game against league leaders Saracens.
"It is our first game at the Stoop this season and we like playing in front of our fans so we will want to put on a show," Kingston said.
"It will be a monumental battle as we beat them at the Stoop last year in an amazing game of rugby."