It's the first time in snooker history that two official maximums have been made on the same day.
Welshman Stevens fired the first 147 of his career in the final frame of a 4-0 defeat of Michael Wasley in the first round.
Just two hours later, China's Ding made his third career maximum in the third frame of a 4-0 success over Brandon Winstone. He also made a 133 in the fourth frame.
The two maximums were the 82nd and 83rd in the record books. There have now been five in the past three weeks - that's just three less than there were in the whole of the 1980s.
Ball by ball scoring and results from tournaments