But after a wild game that included Tigers manager Jim Leyland getting ejected and Gary Sheffield's 497th career long ball, instead of a win, all Willis got were a few pats on the back from Leyland and pitching coach Chuck Hernandez.
In the end, the Tigers' bullpen couldn't hang on to give Willis his first win since Sept. 25, 2007, as Detroit fell to the Rangers, 11-8, in the series opener on Monday night at Rangers Ballpark in Arlington.
"I'm really happy about my outing," Willis said. "I was really looking forward to this. I wasn't sure if I was going to pitch in the Major Leagues this year, but it was a lot of hard work and a lot of people believing in me.
"But I want to win ballgames and that's what I'm here to do. I'm disappointed we lost, so we can go back to the drawing board and try and keep getting better."
Willis started the game by issuing a leadoff walk to Rangers second baseman Joaquin Arias, but then retired the next eight batters.
The most impressive at-bat for Willis, though, came in the fourth inning. After issuing his third walk of the game, Willis struck out former All-Star Hank Blalock with a 93-mph high-and-tight fastball.
But that strikeout was followed by another walk. Then, Willis' only real mishap occurred, when he served up a fastball to Rangers' third baseman and No. 8 hitter Travis Metcalf, who sent the ball into the left-field seats for a three-run home run.
Still, Leyland decided to stick with Willis for the fifth inning, and it paid off. Willis started the inning with another walk, but then retired the next three batters and left the game with the Tigers (70-79) ahead of the Rangers (74-77), 4-3.
"In the fifth inning, I was really pleased because I didn't leave him in just to get a win," said Leyland, who added that Willis would start on Sunday. "Hopefully, we can look back and that inning will get him over the hump. I don't want to get over-excited, but I'm very pleased and it's something we can build on."
For Hernandez, the biggest thing Willis can improve upon is his delivery. The Tigers' pitching staff has been working to simplify Willis' delivery, so it becomes easily repeatable.
"When he was in the stretch, he was not going to the highest points, which was good," Hernandez said. "It was more under control. We still have a lot of work to do, but this was a very positive outing. I don't think Dontrelle has left a Major League clubhouse feeling as good as he does tonight."
The Detroit bullpen, meanwhile, isn't leaving feeling very good after giving up two leads late in the game.
The Tigers had a 5-3 lead heading into the sixth, but the Rangers tagged reliever Gary Glover for four runs. Blalock led off the inning with a single, then Glover plunked Max Ramirez on a controversial call that got Leyland ejected. Two batters later, the Rangers' Taylor Teagarden hit a grand slam off Glover to put the Rangers on top, 7-5.
"I think I threw the ball fine, but the results weren't what I wanted," Glover said. "The pitch to Teagarden was a decent pitch, below the knees and out of the strike zone. Teagarden just did a good job of getting the barrel of the bat on the ball."
Detroit, though, responded with two runs in the seventh on RBI singles from Magglio Ordonez and Miguel Cabrera to tie the game at 7.
In the eighth, Placido Polanco gave the Tigers a one-run lead with a single to center off Rangers reliever Frank Francisco, which scored Ramon Santiago.
But that didn't last long, as Texas answered in the bottom of the frame when Teagarden hit an RBI double off Detroit reliever Kyle Farnsworth, who took the loss. Farnsworth (2-3) then gave up a two-run triple to Rangers outfielder Marlon Byrd as Texas sealed the victory.
Asked about the bullpen's struggles, Leyland said: "If you look at our club, that's happened way too often. It's a downer. Nobody is trying to do it. Over the course of the year, we've let way too many leads get away like that. That's what hurts your club more than anything."
Especially when a once promising starter, Willis, pitched well enough to win.
Drew Davison is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.