LONDON — Taoufik Makhloufi experienced quite a range of emotions on Monday. The 1,500-meter gold medal contender was initially disqualified from the Olympic Games when a race official believed he did not try hard enough in his 800-meter heat. He later was reinstated after it was deemed that Makhloufi was hampered by a knee injury. The Algerian jogged almost half a lap in the 800, then dropped out of the two-lap race and wandered back across the infield.

After easily winning his 1,500 semifinal, Makhloufi no longer wanted to compete in the 800. But his national Olympic Committee did not withdraw his 800 entry before the deadline, forcing him to the starting line Monday. The Algerian federation believed race organizers knew of Makhloufi’s knee woes. After reviewing the evidence, officials deemed the injury was genuine and Makhloufi was reinstated, allowing him to participate in Tuesday’s 1,500-meter finals.

The event referee also disqualified Mohammad Al-Azemi of Kuwait after heats Monday. Al-Azemi had finished third in his heat but it was determined that Polish runner Marcin Lewandowski was pushed by Al-Azemi and lost his place. Lewandowski now advances to Tuesday’s 800 semifinal.

King James

Kirani James claimed Grenada’s first medal in Olympic history, leaving the field behind in a drizzle to win the 400-meter gold by more than a half-second. James, 19, the reigning world champion and a two-time NCAA champion for the University of Alabama, finished in 43.94 seconds. Luguelin Santos of the Dominican Republic earned the silver in 44.46. Lalonde Gordon of Trinidad and Tobago got the bronze. The US had won the past seven Olympic titles in the men’s 400, dating to 1984, but no American qualified for the final. That included 2008 champion LaShawn Merritt, who pulled up with an injury in his opening heat.

Tinsley surprises

In the men’s 400-meter hurdles final, American Michael Tinsley surprised the field with a silver, earning the medal with a surge off the final hurdle. He finished in a personal best of 47.91 seconds. “I’ve been dreaming of this moment since I bought my first pair of spikes,” said Tinsley. “I put my life into this. I’ve had to sacrifice so much for this. I’m so proud. I’ve been running my hardest.” The Dominican Republic’s Felix Sanchez earned gold in 47.63. Sanchez, who turns 35 Aug. 30, also was the 2004 Olympic champion. Puerto Rican Javier Culson finished with bronze in 48.10.

Zaripova rolls

Yuliya Zaripova of Russia won the gold medal in the women’s 3,000-meter steeplechase, clocking the fourth-fastest time in history. Zaripova won in 9 minutes 6.72 seconds in cool conditions in the night session. Habiba Ghribi of Tunisia took silver in 9:08.37 and Sofia Assefa of Ethiopia finished third in 9.09.84 . . . Nadzeya Ostapchuk of Belarus won the women’s shot put gold medal, pushing New Zealand’s Valerie Adams into second place. The 31-year-old Ostapchuk, world champion in 2005, had the best mark of 21.36 meters, or 70 feet 1 inch, on the third of her six attempts. Adams, who came to London as the defending Olympic, world, world indoor, and Commonwealth champion and on a long winning streak, settled for silver with a best shot of 20.70 meters. Russia’s Evgeniia Kolodko took bronze with her last throw of 20.48.

Defending champ out

Defending Olympic 50K race walk champion Alex Schwazer was caught doping in Italy and won’t compete in the men’s event on Saturday. The Italian Olympic Committee said Schwazer, 27, had admitted to doping and been removed from the team. Schwazer also had entered last Saturday’s 20K walk, but withdrew citing a cold, according to the official London Olympics website . . . Olympic officials sharply criticized a man who was arrested for throwing a plastic bottle on the Olympic track before Sunday’s men’s 100-meter final, but competitors said the unpleasant incident did not affect the showcase event. Sebastian Coe, chairman of the London organizing committee, said there would be ‘‘zero tolerance’’ for anti-social behavior. London police said they arrested the man, who has not been identified or charged. The suspect was reportedly hit by Dutch judo champion Edith Bosch after he threw the bottle. ‘‘I said to people around me that he was a peculiar bloke,’’ she said. ‘‘Then he threw that bottle and in my emotion I hit him on the back with the flat of my hand.’’ Coe said there was some ‘‘poetic justice’’ that the suspect was sitting next to an accomplished judo star.