SAN DIEGO—On an uncharacteristically soggy afternoon in Southern California, Sonny Gray did not have his best stuff, but he had enough to win.

Friday was opening day in college baseball, so it's only natural that Gray was not yet in midseason form. After sitting through a long, three-run top of the first inning, the junior righthander surrendered three runs of his own in the bottom of the frame, then settled down to lead No. 4 Vanderbilt to a 4-3 win against San Diego in five innings, before heavy rain abbreviated the contest.

Gray, a first-team preseason All-American, pitched at 92-93 mph on Friday, shy of the 93-96 mph velocity he held deep into games late late spring and during the summer. The Commodores failed to execute a couple of makeable defensive plays in the first, helping a potential 1-2-3 inning turn into a three-run frame, keyed by Zach Kometani's two-run double to right field.

But Gray buckled down and did not allow another hit over the next 3 1/3 innings. He spotted his fastball well and used his vicious 81-83 mph curveball to strike out two batters in each of the next three frames, then departed with one out in the fourth after reaching his pitch limit (85).

Vandy, meanwhile, broke the 3-3 tie with a run in the third on Connor Harrell's RBI single. Gray and reliever Will Clinard made the lead stand up until the rain ended the affair.

"(Gray) did a really nice job after the first inning," Vanderbilt coach Tim Corbin said. "He came back, he didn't get shook—that's kind of the makings of an older kid. He kept us in the ballgame long enough we could scratch out a few runs and win the ballgame."

Even without his best stuff, on a day when conditions were not conducive for dominant pitching, Gray demonstrated maturity.

"It's still early in the year, but the biggest difference in Sonny from last year even to this year is the pitchability," Corbin said. "The pitchability to add and subtract from the fastball and throw more to spots, and keep the infielders and outfielders in the game; rather than just trying to get, just trying to get the outs, more than anything. I'm just happy he came back; it was a team win."

Two other key developments for the Commodores involved the top two hitters in their lineup. Freshman left fielder Tony Kemp led off and drew three walks in four plate appearances. In the second he stole second base easily, then took third on a ground out to third base, demonstrating advanced baserunning instincts.

"It's the same instincts he showed me when we saw him play as a ninth grader," Corbin said. "He led off for his varsity team as a ninth-grader. The first time I ever laid eyes on him he stole home. He's a very mature kid; he's got a big personality. He's a good little player, he does what he has to do in that leadoff spot."

No. 2 hitter Jason Esposito is more of a known commodity, as a second-team preseason All-American. But major league scouting directors voted him onto the second team as a third baseman, and Friday he started at shortstop. Esposito is an elite defender at the hot corner, but the early returns on the move to short are encouraging.

In the fourth inning, Esposito made a backhanded stop deep in the hole and then made a sensational jump-throw across his body to throw out Julian Duran at first base. Esposito, who stole 30 bases in 33 attempts last year, is clearly a very good athlete, and his athleticism was on full display on that play.

"The thing about it is he's played shortstop before," Corbin said. "He's a left-side position player, in my opinion. Even when he played third base, he played the position so deep that he was almost a shortstop playing the 5-6 hole. I just felt like his comfort level—and he told me at the beginning of the year, 'Give me a shot at shortstop, I can do it.' He's got a very accurate arm, he's got great range, he's got good hands, very forgiving hands. At this level, you try to put your best athlete in position to handle the ball the most, and he can play that. I presume he'll get a whole lot better as the season progresses."