Key point performances sees Medvedev progress
Sinner marginal favourite over Fritz
Alcaraz should see of threat of Auger-Aliassime
Outcome could have been very different for Medvedev
In the first two matches of the round, Frances Tiafoe and Daniil Medvedev progressed to the semi-finals, although in Medvedev's case, he was arguably fortunate to prevail in straight sets.
The pre-tournament favourite faced break points in four consecutive service games in set two, including holding from *3-4 0-40, and his victory was earned by better performance on key points than opponent Alejandro Davidovich Fokina.
This win makes Medvedev the outright favourite at 2.26/5 on the Exchange, but Carlos Alcaraz 3.185/40 is likely to go shorter than Medvedev if he wins tonight against Felix Auger-Aliassime. That's the later of the two quarter-finals, which start later tonight - the first is at 2200 UK time.
Sinner with edge over Fritz
That first quarter-final looks competitive, between Taylor Fritz and Jannik Sinner, and it's Sinner who is the slight 1.834/5 favourite to make the semi-finals. Fritz has now crept up to a career-best number five in the world and beat Sinner as an underdog at this venue in late 2021 when the tournament took place later on in the season.
Fritz is 12-2 since his shock loss to Alexei Popyrin at the Australian Open in January, albeit as a solid or overwhelming favourite in all 14 matches.
Sinner has also been in strong form post-Australian Open, with consecutive finals indoors (one title) in Europe in February, and is yet to drop a set in this event so far, so there should be a high-quality match in prospect. Sinner's better return data gives him the edge, numbers-wise, so it's pretty difficult to dispute the Italian's status as favourite here.
Alcaraz strong favourite to get past Auger-Aliassime
Following this, Alcaraz is a strong 1.331/3 favourite to see off the threat of Felix Auger-Aliassime. Interestingly, Alcaraz has lost all three career meetings, including two when he was ranked number one in the world, although both of those were on indoor hard courts - likely much quicker than the slow outdoor conditions here in California.
Alcaraz hasn't dropped a set to get to this stage, while Auger-Aliassime edged a nail-biting final set tiebreak against Tommy Paul in the previous round. That match lasted almost three hours, so it will be fascinating to see how the Canadian can back up such an epic against the world number two.
As I've said throughout the week, the slow conditions should be just to Alcaraz's liking, and he's running at 119% combined service/return points won in his three matches here so far this year, without having his serve broken.
Given this, and the clear discrepancy in data between the duo over the last year or so, and again, it's tough to make a case for the market having made a huge mistake with their pricing here.