By Alan Baldwin

RIO DE JANEIRO (Reuters) - U.S. team mates Michael Phelps and Katie Ledecky moved on from a golden Sunday, somewhat creakily in the case of the former, and returned to the Olympic pool in search of individual glory on Monday.

Ledecky, who won the women's 400 meters freestyle gold in world-record time late on Sunday as well as a 4x100m relay silver on Saturday, was back in action in the afternoon's 200m freestyle preliminaries.

''It was tough coming off last night, but I think I got my lane for semi-finals tonight, so it should be good,'' said the 19-year-old who set the fastest time of one minute 55.01 seconds in the heats and is on for a golden freestyle treble in Rio.

Italy's Federica Pellegrini, who set the world record of 1:52.98 in 2009 in a now-banned synthetic body suit, was fifth fastest and expecting fireworks in Tuesday's final.

''I think it will be the fastest 200 final in history, we never had such high performances in heats,'' she told reporters.

Phelps, who celebrated the 19th Olympic gold of his career in Sunday's 4x100m relay, faces more of a battle as he chases what would be his first individual medal of these Games.

The 31-year-old, in his fifth Games, was fifth fastest in the 200m butterfly -- the first event the world record holder ever raced at an Olympics in 2000 -- but feeling the pain of a late night in the pool.

His 1:55.73 was a second slower than the 1:54.73 of pace-setting Hungarian Tamas Kenderesi, whose compatriot Laszlo Cseh was second fastest and sensing an opportunity.

''I think I'm capable of doing that but we will see,'' said Cseh when asked whether this was his moment to beat Phelps.

South Africa's Olympic champion Chad Le Clos, who beat Phelps in London 2012, eased into the semi-finals with the third best time of 1:55.57.

''I think I probably got to sleep at about 3am and I was on an 11am bus,'' said Phelps. ''So, quick turnarounds. But the good thing is there is a long time between prelims and finals and we are able to rest.

''Hopefully I can get home and get a quick nap in and be back here ready for tonight.''

The semi-finals start at 23.10 local time with the final on Tuesday.

In other heats, newly crowned 400m individual medley champion Katinka Hosszu of Hungary set an Olympic record as she dominated the 200m IM prelims with a best time of 2:07.45.

Britain's Siobhan-Marie O'Connor was second fastest.

Hosszu holds the world record in the event of 2:06.12, set last year when she won world championships gold.

(Additional reporting by Mark Trevelyan and Mary Milliken, editing by Neil Robinson)