The 6-foot-10 Dieng didn't score, only took one shot and had six rebounds as the Cardinals rallied to beat Wichita State.
Dieng said he knew he "took the night off."
But he made up for it on Monday. Dieng played a monster game as the Cardinals claimed the national title with a win over Michigan. He was 4 of 6 from the field and finished with eight points, eight rebounds, six assists and three blocked shots.
"Gorgui was brilliant," U of L coach Rick Pitino said. "He played terrific."
Dieng was 4 of 6 from the field, including three jumpers that kept the Wolverines defense off balance. He scored six points in the second half.
The native of Senegal finished the NCAA Tournament 24 of 31 from the field, which is 77.4 percent. He tied for the sixth best field-goal percentage for a single NCAA Tournament in history.
"I just had to come out and play my game," Dieng said. "I wanted to do whatever I could do to help this team win."
Dieng averages 10 points a game in the tournament and also had 42 rebounds, 12 blocked shots and 10 assists. He finished the season with 10.2 points and 9.5 rebounds a game on the season.
"It's pretty fun now," Dieng said. "I can't believe we made it this far."
Dieng has one more year of eligibility remaining but went through Senior Day festivities last month at the request of U of L coach Rick Pitino. He's expected to be a first-round draft pick if he enters his name in the NBA Draft and Pitino told him "if he's a first-round pick, then he needs to go."
Pitino said on Monday night that he would advise Dieng, Russ Smith and Chane Behanan to test the waters. But he said he expects two of the three to return.
When asked about his future, Dieng just laughed. He never gave a straight answer but kept talking about how much he liked Louisville.
"I am really happy to be a Louisville Cardinals, I am happy to play for this team," Dieng said. "Being in college is fun."
While it certainly doesn't mean anything, Dieng waved to a group of local reporters as they left the locker room and said, "See you next year, in Louisville."