It looked like Ish Smith had beaten Klay Thompson along the baseline and would jitterbug into the lane for an easy layup.

But Thompson might have just been toying with Smith. The Warriors' shooting guard glided with recovery speed and then extended through the air to swat away Smith's attempt at a reverse layup.

The play Sunday night was a perfect cap on a dominating quarter in which the Warriors allowed Phoenix to score only one field goal for 6 1/2 minutes and forced seven turnovers.

It was also a reminder that the play would not have happened two years ago.

"Klay has made himself a big-time defender," Warriors head coach Mark Jackson said. "He does a great job of guarding the best perimeter guy on the other team. He has size, length and deceptive athletic ability. He pays attention to game-plan discipline, and he's able to get back into the picture with smaller guards and contest shots.

"The amazing thing about it is that he didn't come into the league that way. It's awfully impressive the commitment he's made and how dedicated he is to being a big-time defender."

Thompson will be reunited Tuesday night with one of the first people to impress on him the need to become a better defender when Monta Ellis and the Dallas Mavericks come to Oracle Arena.

Ellis, the scoring dynamo who spent his first 6 1/2 seasons with Golden State, started ahead of Thompson in 2011-12 and consistently overwhelmed the then-rookie during practices. Thompson already had a proven shooting skill that promised to keep him in the league for years, but knew he had to develop his defensive abilities to be considered an elite player.

"He's one of the quickest guys in the NBA, so (playing against him) helped me right away - right when I stepped foot into this league. It was really important," Thompson said. "It's cool playing against him now, because he's still a tough cover."

Ellis was sent to Milwaukee before the trade deadline during Thompson's rookie season - a deal that allowed the Warriors to add a legitimate center in Andrew Bogut and also opened up a starting position for Thompson.