Mistake from Carter! He's up on his fingertips to rest the cue and play for the pink into the left centre pocket.
As soon as the cue ball makes contact, he knows the pink has missed with too much cut.
It bounces back off the jaws and it's Maguire now with the chance to go into the interval level.
Uh oh. The Scot has left a rather simple long pot on for Carter into the left corner pocket after missing a red of his own.
Plenty loose reds in the bottom half of the table too if Carter can make the most of the chance.
Maguire with a wry smile as he takes his seat.
Point on the board in frame four for Carter as he takes his first chance at a red.
Nothing more to add as he plays safe to baulk. Maguire could do with a pot soon here.
Guess that little exhibition-style effort at the end of frame one has worked well for Carter.
He's looked assured since dropping that opening frame.
He'll now break in frame four - the last before the interval.
No perfect ending for Maguire as Carter is the next to take red and the frame with it.
He adds to his final tally in frame three but it didn't matter anyway.
In the blink of an eye, he's turned the match around in the early stages and takes a 2-1 lead.
Or not! Maguire can't capitalise on any of the reds and leaves the cue ball near the baulk line.
Carter takes that and the brown to move further clear.
Now in a safety battle with Carter 66 ahead and 67 left on the table. Maguire needs a perfect finish, made tricky with the black close to the bottom cushion.
Ooh, Ali! A break of 54 comes crashing to an end when stretching and using a long rest and extension to pot what would normally be an easy red.
But he has jawed it and immediately rests his head on the table.
Maguire comes back to the table 61 behind and with 75 on the table. That red was almost a frame clincher for Carter. Maybe some fight in this frame yet....
It's actually worse than that.
He misses the reds with his first two attempts before eventually catching the furthest red to the right in the pack quite thick.
That leaves the cue ball down the table, having already handed Carter eight points.
A good red from Maguire but he's immediately put under pressure by Carter who snookers at the baulk cushion when allowed onto the table.
He knows getting out this snooker could leave a pot on for Carter too, if he catches any of the reds full on.
Maguire to break in frame three.
Brilliant from Carter and a great response to that opening frame 84 from Maguire.
He puts in a 111 break to level up this semi final in quickfire fashion.
His 433rd career century for Carter.
Not much in the way of drama so far, they're both taking their chances in the balls when they come.
An ongoing break of 53 for Carter who is punishing Maguire for that missed red.
That looked a bad miss at the time, especially how strongly he'd started.
It looks like Carter is going to see this frame out and level the match here.
Maguire's first mistake, missing a red.
Though it's the only loose red on the table, with the remainder still in the pack. Carter will take that loose red but he'll need to be good to break them up and rely on a bit of luck to leave a pot on.
Blimey, what a pot again from Maguire.
It wasn't a bad break from Carter but the one loose red on the table is there for Maguire and cross-table he sinks it into the right corner pocket.
Another chance for him....
Carter to break in frame two.
A decent exercise for Carter in the end with a clearance of 49.
Maybe just a bit of mind games to Maguire that he can't afford any slip ups.
Nevertheless, the Scot takes the opening frame.
Well, that's one way to do it!
Just as the first semi final started, Ali Carter had one visit and made a mess of a long pot.
He had to sit and watch as Maguire put the frame to bed with a break of 84.
Maguire misses an easy black but that won't matter. Carter does come back to the table, however just to get a feel for potting balls and the table.
Maguire's break is fine but it leaves an outside chance of a pot for Carter.
It's long and towards the right corner pocket but it rattles the jaws and bounces to safety.
Maguire gets a sniff of a long pot and he takes it. Little chance to get an early chance amongst the balls.
Stand-in MC, Ken Doherty welcomes the players onto the floor.
It'll be Stephen Maguire to kick things off, breaking off in frame one.
First to six, here we go!
Neil Robertson has tweeted his appreciation for Mark Selby.
Selby's win earlier meant Robertson banked the £150,000 BetVictor bonus.
Not far away from a start. That 7pm start had me fooled as much as the next person.
Stephen Maguire heads into tonight's semi final knowing it's a huge opportunity for him on this stage.
Incredibly, it's his first ranking semi final for FOUR YEARS.
Speaking ahead of the action, he said: "I’m looking forward to be at the one-table set-up, someone just told me I’ve not been in the semis for four years.
“If I knew why I wasn’t competing for these events more often I’d change it.”
Luca Brecel's defeat saw him miss out on Welsh Open glory.
It also knocked him out the frame for the £150,000 BetVictor bonus - Neil Robertson has taken that.
But he's also now missed out on a Grand Prix spot with the picking and choosing of events coming back to bite him.
He said: “I’m a bit disappointed.
“I wanted to go to Hong Kong for the Grand Prix. Maybe it’s a bit of karma for not entering all the tournaments this year.
“I’ve skipped 5-6 tournaments. I had my chances. I didn’t take them well. Just a few shots here and there, which didn’t go to plan. Mark is very tough to beat.
“It’s all about building up my game for the World Championship. For me that is the big one. Happy to go there with some confidence and results.”
Brecel said: “I felt really bad in the first two frames, but it’s not an excuse because it went.
“It was difficult to regroup. You want to feel good in these moments, but it is what it is. It’s the first time it’s ever happened.
“I didn’t play well enough. I was playing well enough to win the tournament, but missed too many balls there.”
Mark Selby is in the hunt for another very good payday. But just how much is on the line?
Well, there was a total of £550,400 to be split between the competitors in Wales.
The winner will earn £100,000, while the highest break will earn £5,000.
A full breakdown is: