A Stratford High School coach who was critically injured in an assault Friday night has passed away.

In a statement posted to the Spring Branch ISD website Monday, the Stratford High School principal said 33-year-old Chris Matthews, who taught world history and coached football and soccer, died at the hospital Sunday evening.

Police said Matthews, who is married to a fellow Stratford High teacher and coach, was walking a school mom, Laura Sergant, to her car in a restaurant parking lot Friday night when Sergant’s husband, Ronald Newman, spotted the pair.

Police said Newman, 51, walked up and punched Matthews, knocking him to the ground.

Matthews hit his head on the ground and lost consciousness.

He was rushed to the hospital, where he remained until his death.

Police said they have no evidence that there was any ongoing relationship between Matthews and Newman’s wife, and they have not assigned a motive to the attack.

“This terrible tragedy touches so many lives, and we will have many of our students with a connection to these two employees. We have a plan for today and crisis counselors are here for students and our staff. We will have support here for as long as it is necessary. One of the most difficult things at a time like this is that everyone feels helpless and wants to help in some way,” Stratford Principal Christopher Juntti said.

The principal urged parents to be there for their children and to validate their feelings as they grieve.

“Stratford America is hurting today,” Juntti said.

At the Stratford soccer field Monday, mourners left balloons and flowers in honor of the popular coach, and school officials flew their flag at half-staff.

“I’ve never seen so many people crying before. It’s hard. It’s tough,” 15-year-old Samantha Vargas, one of Matthews’ students, said. “There’ve been about 20 counselors I think just talking to kids who need help.”

Meanwhile, Newman made his initial court appearance on aggravated assault charges Monday. Prosecutors said those charges may be upgraded because of Matthews’ death.

Newman was released over the weekend on $30,000 bond.

A search of Harris County records shows Newman and Sergant have had a rocky relationship.

They filed for divorce in 2002 but apparently dropped the effort, then re-filed and finalized their divorce in 2008.

But three months ago, in October 2010, they remarried.

Newman’s attorney, Sam A. Maida, Jr., released a brief statement on behalf of his client Monday afternoon.

“Mr. Newman and his wife, Laura, and their entire family are devastated at this time and want to express that their thoughts and prayers go out to Mr. Matthews, his family and the entire Stratford High School and local community,” Maida said.

According to Matthews’ “about me” page on the school website, he’d been teaching for nine years, the last five at Stratford.

He graduated from East Texas Baptist University in 2002.

He’s survived by his wife, a 14-year-old son who attends Stratford, and 3-year-old twin daughters.