Poundstone would take second place behind Zydrunas Savickas. On June 29, 2008 during the 2 day Fortissimus contest, Poundstone became the first American to defeat Zydrunas Savickas. Poundstone and Savickas were approximately 40 points ahead of all the other competitors. Poundstone was the only athlete who managed to lift the 517 lb Louis Cyr Stone and secured his victory and title at the "Mightiest Man on the Planet." Poundstone became the 2008 Strongman Super Series champion after accumulating the most points throughout the Grand Prix. 1st at the Mohegan Sun, 2nd at Madison Square Garden, and 4th at Sweden earned Poundstone enough to take the overall title. Poundstone competed in the 2008 World's Strongest Man competition where he and Mariusz Pudzianowski, Poland's then four-time champion would go head-to-head in the final event, the atlas stones, with Poundstone leading in points. In the atlas stones, Poundstone gained the lead, but as he lifted the final stone, the stone slipped, falling to the ground and giving Pudzianowski his record 5th World's Strongest Man title. Poundstone's next challenge was the 2009 Arnold Strongman Classic. With Zydrunas Savickas opting to take a year off, the crown was vacant. Poundstone set a new world record with 15 reps in the circus dumb bell event. Poundstone took first place overall, and became only the third man behind Mark Henry and Zydrunas Savickas to win the Arnold Strongman Classic title since its inception in 2002. In May 2009, Poundstone was scheduled to defend his title at the Mohegan Sun Strongman Championship hosted by Giants Live. Poundstone won five of six events, taking second on one event, and took the overall title. Poundstone also set a new world record on the max apollon's axle clean and press with 415 lbs.  Poundstone competed in the 2009 World's Strongest Man competition, which took place in Malta, being in fourth place after Brian Shaw, Mariusz Pudzianowski and Zydrunas Savickas. Poundstone successfully defended his title at the 2010 Arnold Strongman Classic. Leading up to the last event, the timber carry, Poundstone had a 3-point lead over 6-time champion Zydrunas Savickas. Poundstone won the last event and the overall title for a second consecutive time, only the second man to accomplish this feat at the Arnold Strongman Classic.