Robin van Persie hailed his late winner as a special way to celebrate his first Manchester derby.
The Dutchman's deflected injury-time free-kick earned United a 3-2 win at the Etihad Stadium after City had come back from 2-0 down.
Wayne Rooney netted twice before the break, with Yaya Toure and Pablo Zabaleta snatching goals for the hosts in the second half.
Van Persie said: "We had a really good start, because of Wayne's two really good, clinical finishes.
"We were in control but City always come back. But it's a really special way to end this game, with the three points in a really dramatic way."
Rooney said of his team-mate's winning goal: "We work on that on the training ground and I had no doubt he could score from there."
The Fir Park side claimed their first home victory in over three months in the Clydesdale Bank Premier League with Lasley hitting the decisive strike eight minutes from time.
However, there was still time for one more chance for County but Hollis preserved the scoreline with a superb one-handed stop to deny Scott Boyd's header.
"I was on the line and thought Boyd had scored the equalising goal. I think at that point if it goes in you start to think it's going to be another one of those days," said Lasley. "It was a great stop and he has done very well since he came in, everyone knows Darren Randolph is a top-quality keeper and Lee has filled his boots admirably.
"A save at one end can be as important as a goal at the other and that certainly was the case with Lee's save.
"Anything he was asked to do in the game he did well and the save at the end was probably the most important."
County took the lead after 17 minutes when Rocco Quinn unleashed a sensational 30-yard strike, but their advantage was short-lived as Michael Higdon headed home Chris Humphrey's pin-point delivery eight minutes later.
Nicky Law then capitalised on some slack possession to fire Motherwell ahead in the opening minute of the second half, but the visitors responded positively and Quinn hammered home at the second time of asking to level.
Both sides showed a determination to grab a winner and Lasley clinched the game for Motherwell when he flashed an effort beyond Mark Brown.
Lasley felt Motherwell failed to continue their momentum after Law's goal early in the second half, with Stuart McCall's side looking nervous following Quinn's equaliser.
"We scored a nice goal and probably had a few further chances to take the lead in the first half," Lasley said.
"Funnily enough, after getting the early goal in the second half we didn't really kick-on, and that was a bit disappointing.
"The most important thing was the three points and in the end we were delighted to get the win."
Ross County boss Derek Adams was fuming at his side's defending for all three Motherwell goals.
County now must recover in time for Tuesday evening's William Hill Scottish Cup tie with Inverness and Adams believes they will struggle to progress.
"We need a miracle on Tuesday night. Inverness have just beaten Hibs 3-0 and got back into the first game through two offside goals," said Adams.
"The players have to respond, the three goals we lost against Motherwell were poor goals to lose.
"We can't defend as kamikaze as we did. We're creating openings and were unfortunate not to have scored."
