The Spaniard surged up the leaderboard on Friday by carding a 64, and he followed up with a seven-under 65 on Saturday to move level with Stenson.
The pair are now tied at the top of the leaderboard on 14-under.
A steady opening from Cabrera-Bello included three birdies before the turn, however it was a run of four birdies in his final five holes that really put the Spaniard in a commanding position.
Stenson, who won the Tour Championship last year in Dubai, has never successfully defended a title, but he gave himself a chance of breaking that streak with an error-free 68.
The Swede admitted, though, that he had been forced to dig deep.
"I wasn't as good as I was yesterday, and left a couple of shots out there," said Stenson. "But I'll take it. It's a lot about moving forward on a Saturday.
"It was a good day for me. I thought I hit the ball nicely. I gave myself quite a few chances on the greens.
"So I'll take that and try and have a good day tomorrow.
"Rafa [Cabrera-Bello] has been playing really strong these last two rounds. I might need to get to 20-under, 16-under might be enough - you never know. "
The chasing pack is beginning to grow behind the leaders, with Justin Rose in third, three shots back, while there is a group of four players on 10-under.
A patchy front nine saw Rose card two birdies and two bogeys on Saturday, although he steadied himself to shoot four birdies on the homeward stretch, including at the par-five 18th.
World number one Rory McIlroy is tied for fourth after a second consecutive round of 70, alongside his Ryder Cup winning team-mate Victor Dubuisson, Tyrrell Hatton and Norway's Thorbjorn Olesen.
McIlroy looked well set to challenge after four birdies saw him join Stenson at the top, but double bogeys at 12 and 13 cost him, after wayward tee shots on both holes.
The Northern Irishman rescued his round with two birdies on 14 and 18, but he now has plenty to do.
"I'll just try and get off to a fast start like the one I got off to on Thursday and put some pressure on them [Stenson and Cabrera-Bello]," he said. "I can't afford to just stay patient tomorrow.
"I need to get some birdies from the off and see where we can go from there."