(CNN) -- American Ryan Lochte claimed his third and fourth gold medals in the world swimming championships in Shanghai, and has a possible fifth gold on the horizon.
The 26-year-old, who has overshadowed compatriot Michael Phelps with his performances this week, has already secured victory in both the 200m freestyle and 200m individual medley events.
And he doubled his gold medal tally on Friday with further successes in the 4x200m freestyle relay and the 200m backstroke.
Lochte took the anchor leg in the relay to bring the United States home for a record fourth straight win in the event, clocking a time of 7:02.67 to see off France, with host nation China claiming bronze.
Earlier, he lowered his personal best by nearly a second to beat Japan's Ryosuke Irie and another American, Tyler Clary, to win the 200m backstroke in one minute 52.96 seconds.
Lochte won six gold medals at the 2010 world short course championships, and he believes he has taken that good form through to this season.
He told reporters: "I have a lot of confidence, especially what happened last year -- that was the big confidence boost for me and I'm now just taking each swimming event at a time."
And despite a personal best time in the 200m backstroke, an event in which he is the Olympic champion, he believes he can swim faster.
Lochte told the official USA Swimming website: "I don't think that was a good time for me -- I know I can go a lot faster.
"There are some things I've got to work on, so I have a whole year to work on it, and hopefully I'll improve on that time next year in the London Olympics."
Lochte could still claim a fifth world title when he goes for gold in the 400m individual medley.
The other big story of the day saw only the third-ever dead-heat final -- but the second this week -- as Aliaksandra Herasimenia of Belarus and Denmark's Jeanette Ottesen both finished the women's 100m freestyle in 53.45 seconds.
On Tuesday, French pair Camille Lacourt and Jeremy Stravius clocked identical times to win gold in the men's 100m backstroke.