Doha, Jan 8 (IANS): Second-seeded Rafael Nadal has said he is "very happy" with his strong play on hard courts early in the 2016 season after advancing to the semi-finals of the Qatar Open.

"I'm very happy. It's a great start for (me) this year," the Spanish World No.5 said after defeating 24-year-old Russian Andrey Kuznetsov 6-3, 5-7, 6-4 for his third win this week on Thursday.

He said he was pleased with his aggressiveness and ability to change the dynamics of the match, reports Efe.

Nadal will next take on 94th-ranked Ukrainian Illya Marchenko, who upset Spain's David Ferrer in the first round and continued his surprise run this week by taking out France's Jeremy Chardy 6-3, 7-6 (7-3) on Thursday.

Reflecting back on a frustrating 2015, when his ranking fell to as low as No.10 and he won only minor tournaments, Nadal said Thursday's result showed that he was in a better state mentally.

"Last year I lost a lot of matches like the one today, so I'm very happy," he said.

The Spaniard began playing better toward the end of 2015 and began 2016 in an auspicious fashion by winning an exhibition tournament in the UAE, defeating big-serving Canadian Milos Raonic 7-6 (7-2), 6-3 in last weekend's final.

Friday's other semi-final here will pit Serbian top seed and No.1 Novak Djokovic, a 6-3, 7-5 winner on Thursday over Argentina's Leonardo Mayer, against third-seeded Czech Tomas Berdych, who defeated British qualifier Kyle Edmund 6-3, 6-2.

Looking ahead to the four Grand Slam events of 2016, Nadal said Djokovic was a threat to become the first men's player since Australian great Rod Laver in 1969 to capture the Australian Open, French Open, Wimbledon and the US Open in the same calendar year.

The Australian Open kicks off on January 18.