The Spurs never trailed and led by as many as 23 points in the third quarter on the way to forging a 2-0 lead in the best-of-seven series.
The series now moves to Auburn Hills, Michigan for the next three scheduled games, with the defending NBA champion Pistons reeling after a pair of double-digit losses to start the series.
"We had a great game, but I don't think it's been easy," Ginobili said.
"They're a very professional team, they've been in this situation before.
"We bet that Game Three is going to be very tough."
San Antonio made 11 three-pointers while the Pistons failed to make even one attempt from outside the arc as the Spurs easily withstood a belated rally to cruise to victory.
San Antonio coach Gregg Popovich agreed with Ginobili about how difficult the first two games were despite the lopsided look of the scorelines. San Antonio won Game One by 15 points.
"Nothing's easy," Popovich said.
"It's a lot closer than the score looks I think.
"I think they (the Pistons) had a poor night shooting and we just made some shots tonight."
Bruce Bowen had four of the three-pointers for the Spurs among his 15 points, while Tony Parker added 12points despite falling into foul trouble.
"When we're hitting shots like we were hitting shots, we're really tough to beat," Duncan said.
Antonio McDyess had 15 points and Richard Hamilton had 14 points for the Pistons, while Chauncey Billups chipped in with 13.
However, Detroit just could never quite match the intensity of their opponents from the start of the game.
"They just dominated two ballgames," Detroit coach Larry Brown said.
"Our big problem now is that we're having trouble stopping them. I don't think we've been nearly aggressive as they've been."
The Spurs opened the game on an 8-0 run and never trailed, leading 30-19 after one quarter and 58-42 at the half.
The Pistons just could not keep pace with the Spurs at either end of the court, although they did reduce a 23-point deficit to eight points at 81-73 with seven minutes to play in the fourth quarter.
However, San Antonio moved up a gear and pulled away as the final quarter progressed and the Pistons got into further foul trouble late in the game.
"Every time we chipped away at it (the lead), they delivered another blow," Billups said.
"They were good man, they were good."