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(SportsNetwork.com) - The San Antonio Spurs own the NBA's best record thanks to a six-game winning streak, but they'll face a stiff challenge Tuesday night when they visit the Chicago Bulls.

The Spurs' last loss came Feb. 21 at Phoenix. Since Feb. 1, San Antonio is 13-3 and moved past the Oklahoma City Thunder for supremacy in the Western Conference and the Indiana Pacers for the best mark in the league.

On Saturday, Tony Parker had 30 points and five assists and the Spurs defeated the Orlando Magic, 121-112, at AT&T Center.

Manu Ginobili tallied 24 points, Tim Duncan supplied 11 points and 10 rebounds and Kawhi Leonard added 17 points, seven boards and four assists for the Spurs, who have won nine of their last 10.

Danny Green finished with 12 points, while Tiago Splitter chipped in 14 points.

"We picked our defense up and got a little bit more physical in the second half," San Antonio head coach Gregg Popovich said. "We finally got it done and I'm proud of them for that."

The Bulls have alternated wins and losses over the last five, but prior to that, Chicago has gone 6-2 in its last eight.

After starting a demanding six-game homestand with a loss to the Memphis Grizzlies on Friday, the Bulls bounced back with a 95-88 overtime victory over the Miami Heat.

Jimmy Butler did a fantastic job on LeBron James, holding the two-time reigning MVP to 17 points on 8-of-23 shooting from the field. James also didn't attempt a free-throw in the entire game for the first time since Dec. 2, 2009.

Butler recorded 16 points, 11 rebounds, four steals and one block. His block came against James in the final second of regulation.

Joakim Noah had 20 points, 12 rebounds, seven assists and five blocks for the Bulls, who have moved into the fourth seed in the Eastern Conference. D.J. Augustin tallied 22 points, Kirk Hinrich added 11 and Taj Gibson grabbed 12 boards off the bench.

This homestand is heavy on title contenders. Memphis is now in the postseason mix, Miami is the two-time defending champs, the Spurs nearly won another ring last season and the Houston Rockets, Sacramento Kings and Oklahoma City Thunder also visit the Windy City on this residency.

"I think human nature would be to exhale a little bit," Noah told the team's website. "The Spurs are playing great basketball and they're coming whether we like it or not, whether we exhaled or not. We've got to fight human nature and be ready for a big game against a team that's going to come in hungry because we beat them pretty good at their place."

The Bulls topped the Spurs by 10 on Jan. 29, but San Antonio is 8-3 in its last 11 in Chicago.