By Lorenzo Recupero, Globe Correspondent

If you didn’t already know, the Dorchester Bears are legitimate in 2012 — and so is senior rusher Robinson Cyprien.

Dorchester, with a convincing 36-24 win over Latin Academy (2-2) in Thursday’s fifth annual Mason Cup played at White Stadium, took over first place in the Boston South league.

Late in the third quarter, as Cyprien peeled off a 75-yard touchdown rush, Latin Academy junior guard Thomas Mano sustained a hit to the chest and had concussion-like symptoms, according to on-field medical staff.

He was attended by paramedics on the field and taken by ambulance to the hospital for precautionary reasons.

Cyprien missed all of last season because of injuries, but the senior rushed for a career-high 279 yards and two touchdowns, including TD runs of 65 and 75 yards.

“I didn’t get to touch the field at all [last year] so I came out and did what the team needed me to,” said Cyprien.

“He just has great moves and is a really talented kid,” said coach Richard Moran. “That’s just a gift [his ability to run], I don’t coach that.”

The Bears (4-0) are undefeated for the first time under Moran and in the driver’s seat in the Boston South with two league wins.

Moran, who is 2-3 all-time in the Mason Cup (named in honor of longtime Dorchester coach Joseph Mason), was happy to be taking the cup back to the school for the first time in three years.

“I’ll take it,” Moran said. “It’s pretty exciting.”

Lorenzo Recupero covers Boston Public school football. He can be reached at Lorenzorecupero@gmail.com. Follow him on Twitter @LorenzoRecupero