"I've been kind of sick for the past few days. Today it kind of ran up on me. Early in the game I started throwing up on the sideline, had to come in and get some treatment," said Allen, who missed the latter part of the second quarter and start of the third quarter.
"I knew I was going to come back in the game. It was just a matter of when. I just tried to get that feeling out of my stomach. When I was throwing up, it was definitely bad. I couldn't really stand up."
After receiving an IV in the locker room, Allen delivered a spectacular scoring grab in the fourth quarter, although it needed video replay to be ruled a catch after he was barely able to tap down his right foot in the end zone before his left foot came down out of bounds.
Allen was confident in his body control, even if the naked eye of the official wasn't able to see it live.
"I was pretty sure I got my right foot down," said Allen who finished with 79 yards on four receptions. "The referee told me he thought my left foot was down first, that's why it wasn't a touchdown."
The play was his 13th career touchdown reception and moved him into a tie with four others, including ex-teammate Marvin Jones, for eighth-most in school history.
Earlier in the game, Allen caught a slant and outraced the Sun Devils for a 44-yard gain, his longest of the season and only the third reception of 20 yards or longer in 2012 for the preseason All-American.
Outside linebacker Brennan Scarlett suffered an apparent broken hand, Tedford said. Scarlett had five tackles, two tackles for loss, and one sack before he was hurt.
Tight end Richard Rodgers, who did not play at Ohio State and only came in late in the fourth quarter at USC because of a foot injury, caught two passes for 14 yards.
Right tackle Matt Summers-Gavin returned to the starting lineup after missing the prior three games with a left knee injury.
Firsts And Lasts
Tight end Maximo Espitia and nose guard Viliami Moala made their first career starts.
Linebacker Nick Forbes blocked a fourth-quarter field goal attempt, Cal's first such block since Sept. 2008.
Arizona State defeated Cal in Memorial Stadium for the first time since 1997 and first win in the series in five years.
Cal dropped to 1-4 for the first time in Tedford's 11-year tenure.
Cal held a moment of silence before the game to remember Ambassador Christopher Stevens, who was killed in a terrorist attack in Libya earlier this month.
Dan Greenspan is the publisher of Cal Sports Digest and writes about the Pac-12 for Fox Sports Next. Follow him on Twitter @DanGreenspan.