The former Aberdeenshire player’s superb 114 spearheaded the charge towards 322-6 before the bowlers completed the job to leave Kyle Coetzer’s side perhaps just one more victory away from glory.
Cross said: “It was nice to pitch in with a few runs for the boys but winning was most important and taking another two points into the Ireland game coming up.
“Kyle got us off to a great start and helped me get settled and it was good to go on and get such a bit total. It’s credit to the guys in the middle order for getting us up there because at one stage I think we were hoping for 280.
“To be honest we’re not seeing today as changing much because we still have to go to Harare and beat Ireland.
“Hopefully we can keep our run going.
“We’ve bowled five teams out now so we’re doing a lot right.”
Defending one their fourth -highest ODI total, the Scots were given an early scare as the UAE openers came out with all guns blazing.
Skipper Rohan Mustafa set the tone with a blistering 32 from ten balls fewer. Partner Ashfaq Ahmed was only a little less punishing with a run-a-ball 30 as the Scottish bowlers struggled to find the right line and length while UAE reached 62-0 in the eighth over.
The breakthrough came when Chris Sole, replacing brother Tom in the team for his first appearance of the tournament, had Mustafa caught on the boundary by Michael Leask. And Sole’s next over brought further success when Ahmed also departed, his attempted pull finding the hands of Craig Wallace.
That double strike sparked the beginning of the end as Brad Wheal, Mark Watt and Safyaan Sharif added a wicket apiece to have UAE struggling on 93-5.
There was a seventh-wicket stand of 105 between Muhammad Usman (80) and Ahmed Raza (50) but Sole (4-68) returned to claim his fourth wicket as Usman lofted a catch to Watt before Wheal trapped Raza in front.
Wheal (2-45) and Sharif (2-36) mopped-up the tail.
Earlier Scotland’s batters had let fly with a barrage of big hits to all corners of the ground.
Cross and Coetzer led the way with an opening stand of 68 in less than fourteen overs.
Captain Coetzer had reached 43 from only 41 deliveries with five boundaries and a maximum before offering a return catch to leg-spinner Imran Haider.
It was the second wicket partnership between Cross and Calum MacLeod which put the Scots firmly in charge, the pair adding 161 runs.
MacLeod made 78 at a run-a-ball with eight boundaries and one six. Cross, meanwhile, moved effortlessly towards three figures.
Fittingly the landmark came with the last of his four maximums, an earlier one having gone straight over the sightscreen and out of the ground.
Cross’s finest Scotland innings came to an end when he was bowled by off-spinner Mustafa but, by then, he had ensured his side a huge total.
Richie Berrington, breaking the Scottish cap record, and George Munsey made the most of the platform laid by the top order to press the accelerator in the closing overs.
Munsey smashed 30 from only 14 deliveries while Berrington was unbeaten on 37 with a boundary and two maximums.
The win, coupled with Afghanistan’s defeat of West Indies, took Scotland to the top of the Super Six, although they will be joined on the five-point mark by Zimbabwe should the hosts beat Ireland today.