Raonic dropped a 6-1, 6-2 decision to Mardy Fish, who had some mixed performances as part of the U.S. team at the Hopman Cup last week.
"It's been a long time since I've really felt 100 per cent healthy, which I do now," said Fish, who finished in the top 10 for the first time last season. "And now I just need the matches and I need to get going again."
Raonic withdrew from the eight-man tournament after the loss, citing an upset stomach. The world No. 25 from Thornhill, Ont., didn't drop a service game en route to winning the Chennai title last weekend.
Andy Roddick also lost his first-round match, falling to Gael Monfils 7-6 (2), 7-6 (3) in cold, blustery conditions.
Tsonga, who won the Qatar Open in an all-French final Saturday against Monfils, lost 6-4, 6-3 to Austria's Jurgen Melzer.
Australian teenager Bernard Tomic beat No. 7-ranked Tomas Berdych 4-6, 6-3, 6-4.
Monfils caught Roddick by surprise with a between-the-legs forehand to seal the opening tiebreaker after earning four set points with a full-stretch backhand crosscourt winner.
After a close second set, the deciding tiebreaker was lopsided with Monfils earning four match points on Roddick's backhand error. Roddick saved one before Monfils put away the match with a crisp volley.