El Ghazi's early goal at Elland Road secured Villa a 1-0 win at Leeds and lifted them to within one point of the Premier League's top six.
The 25-year-old Holland midfielder played under Bielsa during an 18-month spell at Lille before joining Villa in the summer of 2018.
"He certainly knows how to play against a Marcelo Bielsa team because he's played for one for 19 games when they were both at Lille," Smith said.
"So he knows how they play. I didn't think he had his best performance last week against Leicester, but I knew he was ready for this game.
"I thought he started the game really well. He scored a good goal and had a couple of good efforts as well, and a good all-round performance."
Villa turned in a dogged defensive display in the second half to protect their slender lead and avenge their 3-0 defeat to Bielsa's side in October.
Smith was delighted for his players. He said: "Enormous credit because they're a very good team and very few teams will restrict Leeds to as few chances as we did tonight.
"I thought we got our tactics spot on tonight. First half, certainly the first 15 or 20 minutes, we went and pressed them as high as we could and restricted the distance and space for them to play in, which they're very good at.
"The back end of the first half became a little bit stretched and they had a couple of chances in that period.
"Second half we gave more of the ball up and defended in a lower block and the players took responsibility and restricted them to few chances."
Smith added: "I think he will have been impressed and I think he'll have been impressed with Matt Targett, the left-back as well, who's having a fantastic season.
"There were some really good performances out there today. I wanted to start with an intensity, I didn't feel we had done that in the last two games.
"We've done that today and got a very hard-fought victory."
Leeds' see-saw first season back in the top flight continued as they were denied back-to-back home wins after Tuesday's 3-0 defeat of Southampton.
Bielsa's side did not hit the same heights, but the Argentinian did not think his team deserved to lose a 13th league game this season.
"We played better than the opponent," Bielsa said. "We had many minutes of dominance. Very few where we were dominated.
"In the first half we created more chances than they did, even if they scored a goal."
Bielsa acknowledged his side did lack the killer pass or creative spark in the final third.
"All the crosses, passes from out wide, into the centre, were imprecise," he added.
"In the set-pieces, of which we had plenty, we were also not managing our best. But to summarise, it was a game we did not deserve to lose."