Son struck the second goal as Spurs coasted to a 4-0 win over Bournemouth at White Hart Lane on Saturday, closing the gap on Chelsea to four points before the league leaders lost 2-0 at Manchester United on Sunday.
Son is also closing in on a 31-year-old record after taking his tally to 19 for the season in all competitions - level with Cha Bum-kun, who scored 19 times for Bayer Leverkusen in 1985-86.
One more goal for Son would make this campaign the most prolific to date from a South Korean in European football - somewhat of a surprise considering the 24-year-old made a difficult start to life in England as he considered leaving following an underwhelming 2015-16 campaign.
Crooks praised the 24-year-old for stepping up for Mauricio Pochettino while Harry Kane was injured, with the former Spurs forward writing for BBC Sport: "Tottenham's win against Bournemouth was a walk in the park and it was Heung-min Son who led the Cherries by the nose.
"I must say the Lilywhites are playing some wonderful stuff at the moment but Bournemouth didn't help their cause one little bit.
"There are a few players in the Tottenham set-up who have distinguished themselves this season but the most improved Premier League player in my opinion is Son.
"He was brilliant against Bournemouth and seldom lets Mauricio Pochettino down when called upon."
Crooks also had advice for Bournemouth boss Eddie Howe, who has seen his stock fall since being linked as a potential successor to Arsene Wenger at Arsenal last year.
The Cherries look set to avoid relegation as they sit eight points clear of the drop zone with five games remaining, but Crooks has called on Howe to reorganise his defence to avoid potential heartbreak.
"Another manager who had done a wonderful job is Bournemouth's Eddie Howe but he really must do something about his goals-against record," Crooks added.
"It doesn't help when your captain and arguably best defender cannot determine whether his team-mate had the last touch before letting the ball roll out for a corner.
"It was patently obvious the ball came off Harry Arter's boot. If Simon Francis thought he could kid referee Michael Oliver by letting the ball out of play then he made a big mistake.
"But if that wasn't bad enough, Bournemouth had seven defenders marking five Tottenham attackers at the ensuing corner and the ease with which Mousa Dembele lost his markers to put Spurs in front was quite alarming."