It’s late in the fourth quarter of football’s 24-20 upset of then-No. 8 California. The Golden Bears’ speedy wideout DeSean Jackson takes a pass from quarterback Nate Longshore and darts 63 yards down the left sideline, leaving Wildcat cornerback Antoine Cason in his wake for the go-ahead score.

Thankfully for Cason – “”It felt like I got stabbed in the heart,”” he said at the time – a replay showed that Jackson stepped out before tiptoeing into the end zone, negating the score and propelling Arizona to its second straight upset win on Homecoming.

But replay or not, the fact of the matter remains that Cason got beat, and Jackson’s speed made the difference.

If Fred Harvey has anything to say about it, that’ll never happen again.

Cason joined Harvey’s track team three weeks ago and has been practicing with his new teammates ever since.

“”After this year of him running track, what he’s going to be able to do on the football field is going to be mind-boggling to people,”” the UA track and field coach said. “”There will not be anyone that’s going to flat-out beat him.””

“”When it comes to football, no receiver’s going to be able to turn around, open up and go, and have (Cason) not go with him,”” Harvey added.

Last weekend he competed in his first collegiate track meet, when he qualified for the final heat of the 55-meter dash with a time of 6.54.

But in that final, nerves got the best of the Thorpe Award semi-finalist, who was flagged for a false start.

“”It was a different experience for me,”” said Cason, who’s been lifting each morning with the football team before heading to track practice in the afternoons. “”I hadn’t competed in a collegiate-level track meet yet, so it was different. I got too antsy.””

“”He took it on the chin in his first race,”” Harvey said, “”but that’s to be expected, because he hasn’t – in football, you don’t do anything competitively beyond 40, and that’s 40 yards, let alone 40 meters.

“”For him to really have an understanding of what to do from that point on, you’re asking a lot.””

But this endeavor isn’t entirely new. In addition to starring in football at Los Alamitos High School in Long Beach, Calif., Cason ran track all four years – and in middle school before that.

So when he arrived on campus as a freshman in 2004, Cason approached Harvey about joining the track team, but UA football coach Mike Stoops wanted to make sure Cason got his defense down. Because track’s season overlaps with spring football, it made it difficult to do both each spring.

After three seasons in the football program, and with a firm grip on Stoops’hilosophies, things finally worked out this track season.

“”It was something that I always wanted to do,”” said Cason, whose brother, Dione, ran track at Washington State, “”and now I finally have a chance to do it.””

Cason’s arrival has also brought the limelight to Roy P. Drachman Stadium.

Yesterday a TV crew dropped by the track, its lenses pointed at Cason. Hurdler Dan Cook walked past the cornerback, eyeing the camera.

“”You’re such a celebrity,”” he said drily.

Cason simply shrugged, smiling.

“”Obviously, I like the attention because it brings more notoriety to what we’re doing out here,”” Harvey said. “”The bottom line is he really can help us. He’s going to run fast.””

Harvey’s tutelage will in turn help Cason – or at least that’s the plan.

“”That’s fairly true, ‘Speed can’t be taught,'”” Cason said. “”But they can teach you technique errors that you’re making and increase your speed.””

Harvey said of Cason: “”Now that he’s finally out here, not only will he help us in a lot of different ways, he’s going to be able to really increase his value as a football player.””

Aside from the whole learning-to-become-a-track-athlete thing, the transition has been seamless.

“”He fits in on this team as if he’s been here for four years,”” Harvey said. “”Everyone loves him, he knows everyone, they communicate well. He’s a person that brings a lot of confidence to a team.””

It’s the adjusting to competing off the football field that’s been the most difficult.

“”I hadn’t ran in three years,”” Cason said. “”It’s very different, from workouts, to teammates to coaches – coaching styles – the little mechanics that you learn here that I didn’t learn in high school.

“”I ran real well in high school, but it was back to square one again (in college), because I had to re-learn how to compete in track,”” he added. “”I’m just used to the football field, and that’s where I’m most comfortable.””

As the season wears on, Harvey envisions Cason becoming a piece in the Pacific 10 Conference championship puzzle. For now, he’s just looking forward to his newest sprinter building on last week’s “”stepping stone,”” as Cason called it.

“”The first couple sessions, it was a little shaky, because he hadn’t run anything literally over 40 or 50 yards,”” Harvey said. “”So now you’re in there and you’re having to race against guys. … The transition now – he’s gotten through a lot of the soreness, he’s understanding how to let his speed out. And that’s been huge for him.””