Vladimir Guerrero hit his first home run with the Orioles, who rebounded from deficits of 2-0, 4-2 and 5-4.
Baltimore took two of three from the Tigers after opening the season with a three-game sweep in Tampa Bay. The Orioles didn't win their second series last year until May 13.
Alex Avila homered for the Tigers, who host Kansas City on Friday after going 2-4 on the road to open the season.
Baltimore sent 10 batters to the plate in the seventh. After Brian Roberts and Nick Markakis reached against Brad Thomas (0-1), Guerrero singled in a run off Enrique Gonzalez and Jones hit a sacrifice fly for a 6-5 lead. Reynolds followed with a two-run double and Cesar Izturis capped the uprising with an RBI single.
Jim Johnson (1-0) pitched 1 2-3 innings of one-hit relief for Baltimore.
Avila, who had a homer and four RBIs on Wednesday night, again played a starring role for the Tigers. Besides hitting a fifth-inning homer, he began the seventh with a walk off Jeremy Accardo and scored on Austin Jackson's double to left to put Detroit up 5-4.
The lead quickly vanished in the bottom half.
After throwing six innings of no-hit ball on Saturday at Tampa Bay, Orioles starter Chris Tillman gave up four runs and six hits over 4 2-3 innings in his follow-up performance. The contrast was evident at the outset, when Jackson, Detroit's leadoff hitter, got the first of four singles in a two-run first.
Baltimore pulled even in the second. After Guerrero homered to straightaway center, Jones beat out a bunt, stole second and scored on a single by Reynolds.
The Tigers went up 4-2 with a two-run fifth. Avila got it started with a drive over the right-field wall, Will Rhymes walked with two outs and Brennan Boesch chased Tillman with a double to right-center.
NOTES: Baltimore's original lineup had Felix Pie in LF and J.J. Hardy at SS. But Scott (groin) returned from a three-game absence to replace Pie, and Izturis was a late sub for Hardy. No reason was given for the latter switch. ... Detroit placed RHP Ryan Perry (eye infection) on the 15-day DL, retroactive to April 5, and recalled RHP Robbie Weinhardt from Triple-A Toledo. ... The Orioles pulled off a rare 8-9 out on the scorecard when a liner by Martinez bounced out of Jones' glove and was snagged by Markakis. Umpires didn't see the ball hit the wall before Markakis latched on.