Andy Murray wins at Shanghai Masters against Jerzy Janowicz

Murray was in impressive form from the start on Wednesday in Shanghai

Andy Murray produced a convincing display to beat Jerzy Janowicz 7-5 6-2 in the second round of the Shanghai Masters in China.

The Scot impressed from the start and lost just four points on his serve during the opening set.

Murray saved two break points with aces at the start of the second set and broke Janowicz in the fourth and eighth games on his way to victory.

The 27-year-old will now play Spaniard David Ferrer in the third round.

Fifth seed Ferrer earned a 4-6 7-6 (7-4) 6-4 win over Martin Klizan, who served for the match at 6-5 up in the second set before failing to hold and losing the tie-break.

Top seed Novak Djokovic won his second-round match in straight sets, overcoming Austria's Dominic Thiem 6-3 6-4.

The Serb will meet Ferrer or Murray in the quarter-finals if he beats the unseeded Mikhail Kukushkin of Kazakhstan in round three.

World number three Roger Federer survived a couple of scares, beating Argentina's Leonardo Mayer 7-5 3-6 7-6 (9-7).

The Swiss had trailed 4-2 and 5-3 in the first set before battling back to win, and took the third on a tie-break after saving five match points.

However, in the other half of the draw, world number two Rafael Nadal - playing despite being diagnosed with appendicitis - bowed out 6-3 7-6 (8-6) to fellow Spaniard Feliciano Lopez.

Murray is currently ninth in the standings and Ferrer 10th as both bid to try to get into the top eight and secure a spot at the ATP Finals in London during November.

His hopes of qualifying for the finals were boosted by defeats for two of his closest rivals - Milos Raonic, eighth in the standings, retired when 5-2 down to Juan Monaco, while Grigor Dimitov, in 11th, lost 7-5 6-3 to Julien Benneateu.

Other big names to fall at the second-round stage were fourth seed Stan Wawrinka, who went down 5-7 7-5 6-4 to Gilles Simon, and seventh seed Kei Nishikori who lost 7-6 (7-5) 6-4 to Jack Sock.

Wawrinka and Nishikori are both currently above Murray in the "Race to London" standings.

Mayer (right) needed consoling after Federer saved five match points in the final set of their second-round thriller

"All of the players that are looking to qualify for the World Tour Finals will be aware of what's going on," Murray told the ATP tour website.

"But you need to just concentrate on trying to win your matches. That's the best thing that you can do for your chances to qualify.

"It is just giving me a little bit of extra focus and direction for the last few tournaments."

Murray, seeded 11 for the tournament, had beaten Janowicz in a hard-fought encounter over three sets at the China Open just over a week ago but their latest contest was a more one-sided affair.

With his service game in strong order, Murray applied pressure on his rival's serve and had a break point at 3-2 up, only for Janowicz to save it with a well-directed forehand on the way to holding.

Janowicz also faced a break point in his next game but a powerful forehand and follow-up volley again saw Murray denied.

The Pole had been hanging on but his resistance was finally broken when he was serving to stay in the set at 6-5 down.

Murray engineered two break points and won the first to take the set when Janowicz netted a forehand.

Janowicz had two break points in the first game of the second set but they were saved by Murray with aces.

Having gone 3-1 down, Janowicz had treatment on his ankle and his movement appeared limited as Murray completed the formalities to win.

"You need to play a high, high level to win against him," said Murray.

"He certainly doesn't give away many matches during the year. He certainly hasn't given me any matches when I've played against him.

"In these conditions, if you serve well, you can get free points on your serve, and that can help against someone that obviously returns well."