EVANSTON—Northwestern wanted to prove a point against No. 21 Stanford and drove it home with a strong running game and solid defense that produced a season-opening surprise.Or, as defensive end Dean Lowry put it: ”We unleashed a caged bull today.” Freshman Clayton Thorson ran for a 42-yard touchdown while playing turnover-free ball at quarterback, Justin Jackson added 134 yards rushing, and the Wildcats beat the Cardinal 16-6 on Saturday afternoon.If Northwestern felt like a caged bull, well, back-to-back 5-7 seasons will do that. The recent losing ended a five-year run of bowl appearances that included a 10-win season in 2012.Anthony Walker broke up two passes and had a fumble recovery, and Kyle Queiro intercepted Kevin Hogan in the end zone with about a minute left to seal the win. ”It was probably one of the best performances I’ve seen our `D’ play top to bottom against a ranked team maybe in my time,” coach Pat Fitzgerald said. Thorson scored the game’s only TD in the second quarter. He was steady overall, completing 12 of 24 passes for 105 yards, but fortunate not to have any interceptions considering he threw a few into double and triple coverage. ”I thought our team as a whole played well,” he said. ”Our O-line did a great job the whole game. Me personally, I think I can always do a lot better. I missed some throws and some decisions I made weren’t great.” Thorson got high marks from Stanford linebacker Blake Martinez. ”He was commanding the offense well,” Martinez said. ”Keeping that pace going. They never stopped that quick offense. It was cool to see that he was able to do that his first game.” Jackson carried 28 times. Jack Mitchell kicked three field goals, including a career-long 49-yarder that made it 16-6 with 3:38 left in the game, and the Wildcats started the season on a winning note.Stanford, coming off an 8-5 season that snapped a string of four consecutive BCS bowls, clearly has some work to do.Hogan had a rough afternoon, going 20 of 35 with 155 yards and an interception. He was sacked three times.Christian McCaffery ran for 66. But the Cardinal managed just 85 yards rushing and 240 in total offense. ”The bottom line for us is that we have to be efficient on first down,” coach David Shaw said. ”We can’t have penalties. We can’t have dropped passes. We can’t have missed blocks.” The Cardinal showed some of the form that carried them to four straight seasons with at least 11 wins on the game’s opening possession.But Northwestern tightened its defense, forcing Stanford to settle for a 29-yard field goal by Conrad Ukropina to finish a 12-play drive.The Cats tied it on a 31-yard field goal by Mitchell with 52 seconds left in the first quarter. Thorson, who starred at suburban Wheaton North High School about 40 miles from Ryan Field, made it 10-3 midway through the second when he took advantage of a big hole on the left and scored on a 42-yard keeper. NU had a chance to add to the lead after Walker recovered a fumble by McCaffery a few plays later. The Wildcats took over on the Stanford 38, but a 48-yard field-goal attempt by Mitchell sailed wide left with 2:35 remaining in the half. They hung on in the second half and did their best to drive home a point. ”There’s no reason why anybody should have talked about us,” Fitzgerald said. ”We had no evidence from the way that we finished last year.”