Raducanu, who has battled a wrist injury and illness in recent weeks, showed glimpses of her US Open-winning best form throughout her earlier matches, with victories against 20th seed Magda Linette and 13th seed Beatriz Haddad Maia particular standouts.
The 20-year-old looked impressive again in the early stages against Swiatek, matching the Pole from the baseline as neither player looked close to giving up a break.
However, the turning point came in the sixth game of the opening set.
Down 3-2, Raducanu double-faulted at 0-30, giving defending champion Swiatek the space she needed to claim the decisive break.
The world number 77 was simply outmatched from there, ultimately going down 6-3 6-1 in an hour and 24 minutes.
‘”I think overall I can say it was a positive week for me,’ said Raducanu. ‘The team, I think we had a run of three really good matches.
‘It was a good experience today playing Iga on that court at night. I think the conditions are very slow and heavy and favoured her. But, yeah, it’s just good to see where I’m at.
Emma Raducanu speaks out on Iga Swiatek thrashing at Indian Wells
‘I think it’s been a good 10 days. I haven’t trained particularly much before the tournament, but I feel like I’ll probably take a day to recover tomorrow physically, because since the tournament started, I have done a little bit of something every day.
‘So (I will) reset a bit mentally and physically tomorrow, and then take it from there.’
In the men’s draw, meanwhile, Jack Draper was forced to retire in the second set of his fourth-round clash with Carlos Alcaraz at the BNP Paribas Open in Indian Wells.
The 21-year-old Brit was ultimately overcome by an abdominal injury he picked up during his previous match against Andy Murray. He went shot-for-shot with the Spanish world number two in the early stages, but noticeably lagged as the first set went on. Draper’s serve and movement suffered as Alcaraz ran away with the opener 6-2.
Some treatment from the physio in-between sets did little to improve his condition, and the world number 43 was only able to last two games in the second set before retiring.
The result means Alcaraz moves within three wins of regaining the world number one ranking.