Later that night he entered her room and she told the jury she woke up to him sexually violating her.
Judge Evangelos Thomas jailed Foster for a total of six years after awarding a 25 per cent discount for previous good character.
Foster's convictions were challenged at the Court of Appeal in November.
His lawyer, Paul Borich, QC, had argued the trial had "radically departed" from the normal standard to the extent Foster did not receive a fair trial.
Borich claimed there had been a "grave miscarriage" of justice.
He argued the trial prosecutor had tapped into current social themes, to believe the victim and that those that did not were "anti-women".
In the appeal it was submitted inflammatory and inappropriate language was used in the prosecution's opening and closing addresses.
The Court of Appeal's decision, released today, did not agree.
"The term 'helped himself', while perhaps colloquial in nature, accurately reflected the Crown's case against Mr Foster that he chose, notwithstanding her earlier rebuff, to sexually take advantage of the complainant while she was sleeping," the judgment read.
Borich also challenged that some evidence was excluded from the trial, arguing it prevented defence submissions in a way that was contrary to Foster's rights according to the Bill of Rights.
On the same theme, Borich said a screen used in court while the woman gave evidence had obscured Foster's view, interfering with his ability to participate in his own trial.
While the glass was tinted and there were reflections on the glass, the three judges did not consider Foster's view was so impaired as to give rise to any material concerns.
"We accept it is unsatisfactory that the clarity of the view was qualified when the screen was deployed. However, we do not consider its limitations resulted in Mr Foster's fair trial rights being breached."
The judges were "not satisfied there is a reasonable possibility" that other verdicts would have been reached.
Where to get help:
• If it's an emergency and you feel that you or someone else is at risk, call 111.
• If you've ever experienced sexual assault or abuse and need to talk to someone call the confidential crisis helpline Safe to Talk on: 0800 044 334 or text 4334.
• Alternatively contact your local police station
• If you have been abused, remember it's not your fault.