In a game he didn’t want to play, Brady Hoke and No. 21 Michigan defeated San Diego State 28-7 Saturday at Michigan Stadium.

Denard Robinson had three rushing touchdowns — all of them coming in the first half — as the Wolverines improved to 4-0 for the third time in as many seasons. Robinson had 139 of his game-high 199 rushing yards by halftime to help Michigan build a 21-0 lead.

Hoke, the former San Diego State coach, left the Aztecs program to accept his “dream job” at Michigan in January. Hoke tried unsuccessfully to get out of the game in the offseason, which meant he had to face his former players at a school he guided to a 9-4 record in 2010.

The win was the second for Michigan against the Aztecs (3-1), who lost to the Wolverines 24-21 in 2004, the only previous meeting. San Diego State, which defeated Washington State 42-24 last week, was off to a 3-0 start for the first time since 1981.

San Diego State pulled within 21-7 late in the third quarter on a drive that began at the Michigan 38-yard line following a Wolverines fumble, their fourth turnover of the game.

But the Wolverines defense held tight in the fourth, forcing the Aztecs into a turnover on downs in Michigan territory before Vincent Smith’s 7-yard touchdown run stretched the lead back to 21 points with 6:29 left.

The seven points was San Diego State’s lowest output since a 38-7 loss to Utah late in 2009, snapping a streak of 17 straight games of 21 or more points.

The Aztecs, led by Ronnie Hillman’s 110 rushing yards, lost three fumbles and were penalized six times for 55 yards.