The Blue Jays prospect struck out five over six innings and combined with Brandon Dorsett on a one-hitter as Bluefield blanked Princeton, 2-0, in the first game of a doubleheader.
Signed by Toronto as a non-drafted free agent in June 2011, Jensen (2-1) retired his first 11 before Andrew Toles singled with two outs in the fourth inning. An inning later, issued a one-out walk to John Alexander, who stole second and took third on a groundout but was stranded when Chad Nacapoy hit a dribbler in front of the plate.
"I was able to locate my fastball really well, and that really got me through the first three innings," Jensen said. "I really didn't need to throw my off-speed pitch until the second time around the lineup.
"I was able to go in and out really well and my defense was working really well; I got a lot of ground-ball outs. The guys behind me really backed me up."
The 22-year-old right-hander struggled in his previous start, surrendering seven runs on six hits over four innings on July 16 against Elizabethton. He credited a renewed focus on his fastball for the quick turnaround.
"My last start, I really tried to do too much," Jensen said. "The night before, I watched the hitters and they were really aggressive and I thought I could throw more off-speed ... and they hit me around. Tonight, I just stuck by what had made me successful, and that was keeping the ball down and locating my fastball."
Jensen lowered his ERA to 3.51 in six Appalachian League appearances. That's a huge improvement from his rookie season, when he posted an 11.12 ERA in four starts for Bluefield. That performance has proved to be the push the Pennsylvania native needed.
"Last year when I came to Bluefield, I struggled, and that really motivated me," Jensen said. "I want to pitch well and show the Blue Jays what I can do and get a Spring Training invite.
"I think I have to keep working hard and keep locating my fastball. If my fastball isn't working, they're just going to sit on off-speed all night and my whole game is gone. My whole game plan is to keep attacking hitters, staying aggressive, staying ahead and put them away."
Dorsett pitched a perfect seventh to record his first save.
Jacob Anderson hit a solo homer and Santiago Nessy contributed an RBI single for the Blue Jays, who lost the nightcap, 4-2.
Blake Snell, the Rays' No. 9 prospect, did not figure in the decision after allowing three hits over five shutout innings for Princeton.