* Real closing on European and domestic titles
* Ronaldo one goal short of Champions League best (Adds Ronaldo quotes, Puskas record)
By Iain Rogers
MADRID, March 19 (Reuters) - Cristiano Ronaldo's scintillating form and the supporting role played by the likes of Gareth Bale and Karim Benzema suggest Real Madrid have every right to believe a rare treble is well within their grasp.
Barcelona became the only Spanish team to win the Champions League and the domestic league and cup in the same season in 2008-09 but La Liga leaders Real are in a strong position to match their arch rivals after Ronaldo's goals helped them put together a 31-match unbeaten run since the end of October.
The Portugal forward and World Player of the Year has scored 41 goals in 37 matches for the world's richest club this term.
His double in Tuesday's 3-1 win against Schalke 04, as Real secured their place in the Champions League quarter-finals with a club record 9-2 aggregate success, took his tally in the latest edition of Europe's elite club competition to 13.
Coach Carlo Ancelotti deployed Ronaldo in the last 16 first leg even though Real were leading 6-1 from the first game in Germany, when he also struck twice and Bale and Benzema each netted doubles.
"I feel good and the coach, who makes these decisions, decided it was good for me to play," Ronaldo said on UEFA.com.
"I scored two goals and helped my team achieve a very important win to keep our good run going.
"We must continue on this path. Let's see what happens in the next few games."
Ronaldo's opening goal in the 21st minute showcased his ability to time his runs to perfection as he sprinted into the area and clipped a Bale centre into the net.
His second strike 17 minutes from time was classic Ronaldo as he collected the ball near the halfway line and charged past the helpless Schalke players before smashing a low shot into the bottom corner.
"Ronaldo didn't become World Player of the Year for nothing," Schalke coach Jens Keller told a news conference. "His qualities are outstanding."
With 13 goals in seven games, the 29-year-old former Manchester United player has surpassed his best Champions League haul and is one short of the record of 14 set by Barca forward Lionel Messi in 2011-12.
He also climbed above Real great Ferenc Puskas into fourth on the list of the club's top scorers with 243 compared to the Hungarian's 242 but still has some way to go to catch leading marksman Raul who scored 323.
"Cristiano is the best in the world," Real midfielder Casemiro, who had a rare chance to impress on Tuesday with his team virtually assured of going through, told reporters.
"He is a one-man show and an example for everyone," the 22-year-old added. "I learn a lot from him and he is an incredible player."
Real will find out on Friday who they will face in the quarter-finals and they could be drawn against Barcelona or city neighbours Atletico Madrid.
Real host Barca, the last team to beat them, in the La Liga "Clasico" on Sunday, when a win would stretch their lead over the champions to seven points and deal a severe blow to Barca's chances of a fifth title in six years.
Barca are third after a couple of surprise defeats, a point behind second-placed Atletico.
Barca and Real also meet in next month's King's Cup final, a repeat of the 2011 showpiece which Real won 1-0, raising the prospect of a possible four meetings between them in the space of just over three weeks.
"We have to take things step by step," Ronaldo told UEFA.com. "We had a very good group stage, scoring a lot of goals while accumulating points.
"Let's see who we get next but I see the team doing well at the moment and, one step at a time, we will try to achieve our objective of winning three competitions.
"We know that will be difficult but at Madrid we have to aim high. With that attitude, anything is possible."
Record signing Bale, who has started to come into form after an injury-disrupted start to his Real career, has developed a highly effective partnership with Ronaldo and the Wales winger said his confidence was high as the season enters a key phase.
"I am enjoying my game," he told reporters. "We are playing well, with a lot of confidence, and are on a good run. We're coming to a decisive part of the season and we have to keep it going.
"Barcelona is a direct rival and we will try to play a good match (on Sunday) and get the three points. They have very good players but we are focused on our game and on our team because we also have very good players." (Editing by John O'Brien and Ken Ferris)