Lockyer was the toast of the home club after scoring his first goal for the Pirates and later preventing an equaliser.
Lockyer, who played on the right flank, nodded home a Lee Brown cross at the far post in only the second minute and just before half-time he produced an equally valuable defensive header from almost underneath his own crossbar to keep the ball out.
Rovers boss John Ward enthused: "Tom has played much of his youth-team football as a centre-back and his defensive skills came to our rescue.
"It is his day and deservedly so. He works extremely hard in training and I never hear a moment of grumbling from him.
"This was a huge win for us because it puts us on seven points and improves the league position. It's early days, but with players coming back from injury we are starting to gain some momentum.
"It would have been easy for the players to have been thinking about next Wednesday's Johnstone's Paint Trophy tie with Bristol City. But this was the match we needed to focus on and they did just that."