A 22-year-old man is to be sentenced for the murder of a two-year-old boy he "punched or kicked" in the stomach during a "loss of temper".
Joseph Eke inflicted the fatal injuries when he was left alone with Harry House at their family home in Broadmayne, Dorset.
They were left for a few minutes while the child's mother popped to the shops on May 26 last year.
Following a three-week trial, a jury at Winchester Crown Court found Eke guilty of murder and causing grievous bodily harm.
Adam Feest QC, prosecuting, told the court that Harry died as a result of a blunt-force impact to the abdomen, probably by punching or kicking, which was of such force that it split the pancreas in two.
He said: "The defendant attacked Harry in such a violent way he caused multiple severe internal injuries and skull fracture.
"The force would have been severe and significant and in landing that blow or blows on such a small child, that degree of force would have been obvious to the defendant."
The GBH charge related to several broken ribs which were found during a post-mortem examination.
Harry's mother, Lauren O'Neill, 22, told the court how her son went "all floppy" in her arms after Eke told her that he was not feeling well.
She said: "Harry was crying and he spoke to me and said he was okay and then he went all floppy and was making weird noises and his eyes were rolling in his head.
"He seemed to deteriorate really, really quickly.
"He was really, really floppy, his eyes were in his head, he was a funny colour and making funny noises."
The court heard that Eke urged O'Neill not to call an ambulance, telling her that Harry could be put into care.
Eke, of St Lawrence Road, Upwey, Weymouth, denied the offences and told the court: "I didn't kill him, I wouldn't kill him. I wouldn't harm a kid."