Unlike with his topsy-turvy victory over Benoit Paire in the first round, David remained in control of proceedings throughout the match. Profiting from Simon's low percentage of first serves (especially in the first set) as well as from the many unforced errors that Simon committed. Also contrary to the match against Paire, this time the two sets unfolded rather similarly. In both sets, David was able to get an early break, for 2-1 in the first, and for 3-1 in the second set. In each of the two sets David played one poor service game but this time he managed to fend off all of the break points he faced, able to rely on his first serve in those moments (coming back from 15-40 at 4-3 in the first and from 0-40 at 3-1 in the second set). And also in both sets, David then broke serve again, to take the set and eventually, the match.
In short, David was the better and far more solid player, with especially his serve performance much improved, compared to the first round. Before the match, there was a question mark, concerning David's physical state. But he seemed to have recovered from his long match against Paire and that this match only lasted little more than an hour will have surely helped. Whether David will be able to build on this good result we'll see tonight, when it's time for the quarterfinal.
(- That's the short version. I'm ill so bear with me...)