In the straight-set victory, Djokovic won 81 percent of first-serve points, 65 percent of second-serve points and saved 3 of 3 break points (all in the first set), per ATPWorldTour.com.
Djokovic will play Andy Murray on Wednesday, who disposed of Tomas Berdych on Monday, 3-6, 6-3, 6-4.
Coming into the tournament, Djokovic had a 70-12 singles record this season, complete with five singles titles (including the Australian Open title). He's currently ranked No. 1 in the world after moving ahead of Roger Federer.
Coming into the ATP World Tour Finals, Djokovic was also ranked No. 4 on tour in percentage of second-serve points won, No. 2 in first-serve return and second-serve return points won, No. 2 in break points converted and No. 2 in return games won, per ATPWorldTour.com.
Djokovic had won his last 10 matches before losing to Sam Querrey in Paris. He lost to Murray in the U.S. Open final in a thrilling five-set match.
He hasn't been as dominant as he was in 2011, but, then again, that's nothing to be ashamed of, considering he went on a 43-match winning streak at one point.
Here's to hoping Djokovic's next match against Murray will be another thriller. Given they are both ranked in the top three in the world, it's likely that it will be a captivating affair in front of Murray's home crowd in London.