Celtic boss Neil Lennon said his team could have been better but did a "very professional" job after the 1-0 Europa League win against Riga FC.
Lennon said of his side's performance: "It was dominant. We had to be patient, we left it a little bit late to get the winner. We should have had the game wrapped up a lot earlier, we had a couple of great chances.
"I thought the subs did really well when they came on, but the starting XI I felt played very well. Riga set their stall out early and I just said to them 'you're going to have to keep probing, keep wearing them down, make sure the door is shut at the back'.
"It's not an easy place to come and win, and we've done it very professionally, so I'm delighted. It's not an easy game to play, a lot of pressure on us going into the game, but we've negotiated it very well."
He added: "There was a calmness about us. We didn't get frustrated, we kept going.
"There was aspects of our play we can do better. But I felt 2-0, 3-0 wouldn't have flattered us. We missed good chances at big moments in the game, but thankfully we've come up with a brilliant goal towards the end.
"That experience I think has stood them in good stead. We've got another real difficult one next week. I felt the performance thoroughly merited the win."
Lennon said he felt Frimpong made an "outstanding contribution" and said he hoped Elyounoussi's goal "kickstarts his season into great things".
The latter came on in the 82nd minute for Odsonne Edouard, who was back in action after being left out of the 3-2 win over Livingston on Saturday, with Lennon insisting it was to rest the forward.
When asked about Edouard after the Riga match, Lennon said: "I think he's still trying to find his best form.
"He didn't look as sharp as what we expected him to be, but he'll probably get the benefit of the minutes he was on the pitch. But I don't think there's any sort of hangover from the injury he's had.
"There's no substitute for playing and getting up to match speed. We rested him at the weekend.
"There's a lot more to come from him in terms of what he brings to the team. We'll see how he goes on Sunday (when Celtic host Hibernian), if he's picked."
Thursday's contest saw James Forrest come off in the first half, and Lennon said of the winger: "He has bone bruising, so we'll have to scan him either tomorrow or Saturday.
"He definitely won't make the Hibs game, and he may be a doubt for next week but we'll have to wait and see. It's certainly not a minor thing. He's in a lot of discomfort at the minute."