Striker Ulloa broke Doncaster's stern resistance with a 75th-minute header to keep the Seagulls in touch with the play-off places and condemn struggling Rovers to their first defeat in five matches.
And boss Garcia believes that Ulloa's first goal since Boxing Day could be the catalyst for a strong end to the season for the Argentinean striker.
He said: "I hope this will be the start of a long run of goals for him. Leo has been entirely the same player that we know during his goalless run.
"His confidence will be really high after this goal. He has been doing his job for the side really well and I'm sure he will be really pleased with his goal.
"We started really well but when you (miss) a lot of chances you can lose your confidence. We kept playing well and creating chances and finally Leo took his chance well."
Garcia denied that speculation about his future at the Amex - with Swansea rumoured to be interested in hiring the Spaniard after the sacking of Michael Laudrup this week - has affected his players.
He added: "It doesn't affect the players because they know I am with Brighton. They are not new to football. They know how it works, that managers can be sacked at any time.
"So I don't think they will spend any second of their lives thinking about it at all. The players are happy and they know we have a massive game on Tuesday."
Doncaster boss Paul Dickov was disappointed that his side's hard-fought display went unrewarded but remains convinced his struggling side can find a route out of trouble at the bottom of the Championship.
Rovers are without an away win since a 1-0 victory at Sheffield Wednesday in September but Dickov said: "We feel a bit unlucky.
"We were outstanding today. We knew they are a top team and we almost weathered the storm and got something from the game.
"In the second half we caused them some problems. We created more clear-cut chances throughout the game, so we feel that we've been done hard by.
"We've been on a good run lately and I'd like to think anyone that saw us would think that we can compete at this level. We're not stupid enough to dismiss the threat of trouble but we have a good chance of getting out of it."
Dickov hit out at referee Gavin Ward's decision to send off striker Billy Sharp after a tussle with Brighton defender Gordon Greer.
Sharp appeared to raise an arm in the direction of the Seagulls captain in the 86th minute but the Doncaster boss refuted any suggestion it was deliberate.
He added: "I'll be speaking to my chief executive tomorrow and we'll see whether we can appeal. Billy, if anything, has pushed his chest. There's confusion from my players about what the sending-off was even for.
"There were a lot of things with the referee that I wasn't happy about today. At 0-0 we were being punished for time wasting, but when Brighton scored they did the same.
"I don't think (Sharp) should miss three games because it was not a sending-off."