By Steve Keating

SAN JOSE, California (Reuters) - Simone Biles is well on the road to the Rio Games but Olympic champion Gabby Douglas's journey is in danger after a dramatic opening round of the U.S. Olympic gymnastics trials on Friday.

Biles, the three-time all-around world champion unbeaten in major competitions since 2013, looks poised to keep her winning streak intact posting a leading score of 61.850, a full point clear of her nearest challenger Lauren Hernandez heading into Sunday's second round.

A USA Gymnastics selection committee will announce the five member Rio squad Sunday evening.

With 14 women battling for five spots, Douglas, the London Games all-round gold medalist, suddenly finds herself in an Olympic-sized hole sitting seventh after a bumpy night that closed with a fall off the beam.

"I'm just going to take this and not get down and fight for every little thing and just not give up," a clearly shaken Douglas told reporters. "I just have to tell myself that it's not over until it's over.

"I am definitely going to recover because that is what I do, I'm a fighter."

Douglas has developed a well-earned reputation of delivering when it matters most and the stakes could not be higher on Sunday when she will need to produce a bounce-back performance and show women's coach Martha Karolyi she deserves a ticket to Rio.

Certainly Karolyi did not appear ready to throw in the towel on Douglas, offering the London Games darling a vote of confidence.

"I feel like she will have a good presence tomorrow," said Karolyi. "I think her training wasn't so perfect leading up to today and I think in comparison to how she trained she competed well until the last event.

"She will have to perform tomorrow."

Even on a night when she was not firing on all cylinders, Biles was the clear class of a quality field recording the best score on the floor and vault, second on the beam and fourth on the uneven bars to go top the rankings.

Sixteen-year-old Hernandez, helped by the top mark on the beam, scored 60.850 while London gold medalist Aly Raisman sits third on 59.950 followed by MyKayla Skinner and Ragan Smith.

"It’s hard to control the adrenaline and bring it back down because I don’t think any of besides Gabby and Aly are used to that,” said Biles, about competing in front of boisterous capacity crowd of 17,904 at the SAP Center.

"I would sit on the side and almost feel tired. It would be like I did a routine but I hadn’t started it.

"Tomorrow we still have training and hopefully we can perform better in day two."

(Additional reporting Liana Baker; Editing by Amlan Chakraborty)