The forecast for Tuesday suggests that England will need to finish the game in four days if they want to seal a third victory in the series, and although they do not need it to retain the Basil D'Oliveira Trophy, South Africa's target already looks too great in the conditions.
Former Aussie Test quick Jason Gillesie, who interviewed for the England head coach role back in 2015 after an impressive stint at Yorkshire, confirmed to cricket.com.au on Saturday that reports in the United Kingdom linking him to the job were the first he'd heard of the news.
Moeen made South Africa pay for Dean Elgar dropping him on 15 when a low slip chance off Keshav Maharaj did not stick.
Three times Moeen hit Maharaj for six and his confidence, shot selection and execution raised the question of why he is batting down at number eight.
But Moeen took the game to the left-arm spinner, putting on a 58-run partnership with Toby Roland-Jones and eliminating the concern over the rough with positive footwork.
England now lead by 360 runs and have gone off for rain, but there will still be concerns surrounding the top order heading into the Ashes series this winter.
When rain ended the third's play early in the third session, England were 224 for 8 in their second innings - a lead of 360 runs - with Moeen unbeaten on 67.
The current contract of South Africa head coach Russell Domingo expires at the end of this tour.
England was in control for nearly the whole day, except for a short period at the start when South Africa took three wickets in five overs to have England at 312-9.
With England 200-7 at Old Trafford, leading by 336 and in the 63rd over of the day, Ali opened up and launched a huge drive over the top of bowler Keshav Maharaj towards the pavilion.
By that point England's advantage appeared decisive, with Joe Root (49) again to the fore, given the previous highest-successful run chase on the ground is the 294-4 scored by England against New Zealand in 2008.
The visitors added just six runs to their overnight total of 220 for nine before Stuart Broad claimed the final wicket, thus denying James Anderson the five-wicket haul that the home crowd desired.