United were back at Leyton Orient for a league game for the first time since February 2017, with the Blues having become a bit of bogey side for the home team prior to their drop into the National League.
Carlisle had won both of their last two visits, with draws from the corresponding home fixtures, but a steady return to the Football League for the O's meant that the weekend encounter was always going to be a tough test.
United went with three changes as Mo Sagaf and Harry McKirdy came in for Hallam Hope and Stefan Scougall, with both forwards given licence to roam whenever the Blues had the ball.
Jack Iredale was back from his one-game suspension, and he replaced Christie Elliott in the starting eleven.
Orient started well, but crosses into the box were dealt with as Collin commanded his area. Loud appeals for a home penalty were waved away with five minutes on the clock, when Brophy fell, but the referee had no intention of turning the second claim down, which came just 60 seconds later.
Jarrad Branthwaite was shoulder-to-shoulder with Brophy, the same player who had gone down just moments earlier, and looked to the officials as he hit the ground. Josh Wright placed the ball and sent Collin the wrong way to give his side the lead from the spot.
Carlisle had an immediate chance to respond when a long ball sent McKirdy clear on the right wing. He had options, as he dropped his shoulder and angled his run towards the box, but he chose to shoot from a very tight angle and Brill was able to drop low to make the save.
Webster did well at the other end when he beat Harrold to a near post delivery to put the ball behind. The corner was punched by Collin, but he was under pressure and it only went as far as Coulson, who had pulled off his man. The stopper got down to push the resulting volley onto the post and the follow up toe poke brushed the woodwork as the ball made its way into the side netting.
United showed signs of settling as Iredale sparked a move when he carried the ball into the Orient half. He used Sagaf to help to create space, and Thomas called for it when he came deep. A touch to release McKirdy had just too much on it and Orient were able to clear their lines.
The O's stayed forward from a Dayton corner on 25 minutes with plenty of bodies looking to get a touch on the ball. A cut back from the left found Harrold with his back to goal, and he spun to make room for the shot, with Branthwaite tight at his back. The block was made and the Blues sent the ball long as they pushed out from defence.
The visitors used a one-touch approach to try to find a way through midway through the half with McKirdy, Mike Jones and Mellish switching places and exchanging passes. The cross was bent deep by Mellish but the whistle blew for a push as Thomas challenged to try to get there.
There was defending to do for the away team as crosses came from left and right, but they were well dealt with as Webster got his head onto most of what came his way. And a long range effort from Wright had Collin ready to pounce until he spotted that the spin was taking it away from the target.
United had a real shout for a penalty of their own turned down on 40 minutes when Iredale was chopped late by Dayton. The referee said no, and Mike Jones peeled away to pick up the loose ball. He went for it from 25-yards but Brill plucked the ball out of the air.
Carlisle had a scare in time added on for the first half when a 35-yard Thomas free kick was cleared. Brophy led a charge, and he received a great pass to be put clean through on goal. Mike Jones received thanks from his team mates as he made up the ground to put in a vital tackle.
Striker Olufela Olomola came on for the second half, as United changed formation to 4-3-3, and they had an immediate chance to trouble the target when McKirdy stood over a 20-yard free kick after Sagaf had been fouled. His initial effort hit the wall and the second rasper went the same way.
It spun away for a corner and Bridge found an excellent delivery which caused all kinds of confusion. Mellish did well to send the ball goalwards as he fell inside the area, and Jack Iredale was there to sweep the loose pieces into the back of the net as the ball came his way.
The away side looked more confident and Thomas tried his luck from distance as they pushed on in numbers. It skipped off the surface and Brill had to take care as it came low at his legs. Excellent work from McKirdy followed when he turned his marker inside out before bursting into the box. His drilled cross was met by a diving header from Sagaf, but Coulson showed bravery to throw himself at it and prevent what looked a certain goal.
A good spell of pressure from the visitors saw Sagaf and Gethin Jones asked questions from opposite flanks, and a long throw from Iredale had Orient stretched as they once again failed to deal with it. It was sprayed wide to Thomas, and he beat his man before looking to cross at pace. It got caught on his boot and Brill was able to take it under his wing.
The Mint shirts looked good going forward, but McKirdy was asking a lot of himself when he went for an acrobatic overhead kick as a mishit pass from Olomola dropped his way. Brill was beaten, but so was the post.
For all the good Carlisle work Collin was needed to make a magnificent save with just five minutes left to play when Brophy was allowed to run free. It was heading for the roof of the net until the keeper climbed high to palm it away.
But United thought they'd won it when Olomola beat the offside trap to then go on a run. He bore down from a tight angle and Brill had to throw out a leg to send it behind as it appeared to be heading into the bottom corner.
Olomola was thwarted at the near post in time added on, as a fizzed pass came his way, and the corner was punched by Brill before Mellish could connect.
The full time whistle blew with Carlisle in the ascendency off the back of a very good second half performance, and it left them with a point to show for their much improved efforts.
Leyton Orient - Wright (7 pen)
Carlisle United - Iredale (48)
Carlisle United - Sagaf (24), Thomas (70), Webster (80)
Leyton Orient - Brill (gk), Widdowson, Ekpiteta, Coulson (c), Clay, Dayton (Maguire-Drew 63), Happe, Brophy, Harrold (Dennis 72), Marsh (Gorman 83), Wright. Subs - Sargeant (gk), Judd, Turley, Alabi.
Carlisle United - Collin (gk) (c), Branthwaite (Olomola 46), Webster, Mellish, G Jones, Sagaf (Knight-Percival 87), M Jones, Bridge, Iredale, McKirdy, Thomas (Hope 83). Subs - Gray (gk), Elliott, Scougall, Sorensen.
Referee - David Rock
Assistant Referee 1 - Stephen Brown
Assistant Referee 2 - Abbas Khan
Fourth Official - Michael Webb
Attendance - 5,765 (552 away fans)